This week, more than 1,000 people got sick and 16 died in an outbreak of HUS – a disease related to the bacteria E. coli. Initially cucumbers imported from Spain were blamed to be contaminated with the bacteria, but today this theory was proved wrong, and the source of the infection remains a mystery. What exactly is HUS, and what can you do to avoid it?

Initially, Germans have been warned not to eat cucumbers. (Photo by kobiz7)

Danger Level: High

What is it?

Hemolytic Uremic Syndrome (HUS) is a disease that causes anemia, renal failure and a low platelet count in the blood.

Who gets it?

Most cases of HUS develop in young children, but it can certainly happen in adolescents and adults as well.

It can affect men and women alike.

It’s usually not very common, occurring to 0.5-2 people out of 100,000 in the US per year.

What causes it?

The most common cause for HUS is infection with E. Coli bacteria. E. coli (or by its full name, Escherichia coli) is actually a large group of germs, some of them live in the intestines of healthy people. The type of E. coli which causes HUS is a violent type, which produces a toxin called Shiga-Like Toxin. The toxin is absorbed to the blood through the intestines, and damages the cells that create the most internal layer of blood vessels – especially in the kidney but also in other organs. This damage causes all the symptoms of HUS.

You can get infected with this type of E. coli by eating contaminated and undercooked meat or produce, drinking unpasteurized contaminated milk or swimming in contaminated pools and lakes. It can also be transferred by contact with infected people, for example – in day-cares.

E. coli (Photo by Phil Moyer)

There are other not-common causes for HUS, including:

• Other infections: Some other bacterial and viral infections can also cause HUS, but this is much less common.
• Medications: Several medications can (rarely) cause HUS, including birth control pills, some chemotherapy drugs and cyclosporine – which is used to suppress the immune system (for example after an organ transplant).
• Other diseases: Systemic Lupus Erythematosus (SLE), Preeclampsia and inflammation in the kidneys after radiation treatments.
• Some cases are genetic.

How does it feel?

1. Food Poisoning: The first symptoms are food-poisoning symptoms caused by the E. coli bacteria themselves. This can include abdominal pain, a fever, vomiting and diarrhea which usually becomes bloody at some point. these symptoms appear 5-10 days before all the other symptoms.
2. Anemia: This causes the sick person to look pale and be pretty tired, weak and irritable.
3. Bleeding: There might be external bleeding (from the nose of mouth) or bleeding under the skin, which looks like small unexplained bruises. this is caused by a low number of platelets, which are the cells in our body responsible for blood clots.
4. Kidney Failure: Can cause the body to produce less urine.

The story of 16-year-old Aly, who recovered from HUS

How is it discovered?

When suspecting HUS, the doctors will draw some blood. They will check several things: Complete Blood Count will let them know if there is anemia or low platelets, and kidney function tests will determine if there is kidney failure. They will also look at the blood under a microscope. Other tests that might be needed are a urine test (to look for blood in the urine) and a stool sample (to look for the germs).

How is it treated?

The treatment is given in the hospital, and the goal is to relieve the symptoms:

• The most important part of the treatment is dialysis treatments until the kidneys start working again. If the disease is diagnosed early enough, dialysis might not be needed. The doctors can save the kidneys from failing by giving a lot of fluids.
• The anemia is treated with blood transfusions, and the bleeding problems with platelet transfusions.
• Another possible treatment is plasma-exchange (also called plasmapheresis) – in which blood is removed from the body and blood from a donor is returned back. This is used to remove elements that cause the disease from the blood.

Although the cause is an infection, antibiotics are not part of the treatment.

Dialysis treatment.

What happens after treatment?

In most cases (about 90%, and especially in children), if the disease is discovered early enough and treated correctly, the patient recovers. The other 10% might die or remain with chronic kidney failure which will require dialysis treatments for the rest of their life or a kidney transplant. Some of the people who recover will develop kidney problems or hypertension later in life.

The bottom line – how do I avoid it?

The best way to avoid HUS is to avoid food-poisoning with E. coli – this can be done in several ways:

• Treating foods carefully: You should wash hands often when cooking, keep meat in the refrigerator or freezer, wash fruit and vegetables under running water, cook meat thoroughly without leaving pink areas (if you have a thermometer for cooking, cook to a temperature of at least 160°F [70°C]).
• Avoiding certain foods: Especially undercooked meat, unpasteurized milk and cider. Drink only clean water. Remember that the contaminated food will not necessarily look spoiled of taste bad.
• Avoid swimming in dirty lakes and pools.
• If you have diarrhea – wash hands often.

Related posts:

1. Everything You Need To Know About Fast Food – An Infographic
2. In the News – Hodgkin’s Disease
3. Naphthalene Poisoning – When Mothballs Kill More Than Just Moths (As Seen on House MD)

This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!)


On episode 2 of season 2, named “Autopsy”, a 9 year old girl named Andie with terminal cancer (rhabdomyosarcoma) is suffering from hallucinations. Since her cancer was improving, it wasn’t the cause of her hallucinations. Deducing that her cancer has caused a blood clot in her brain, the team do a sort of autopsy while she is living to find out if she indeed has a blood clot in her brain which doesn’t show up on MRI, which she did.

First of all – what are blood clots?

Blood is the red liquid we all know that flows throughout our body in our blood vessels.

When a blood vessel gets injured, the body does all it can to repair the damage. It does this by forming a blood clot (which, in medicine, is called a thrombus). Remember when you were a kid and got wounded? Most of us find out then that the body forms this hardened “plug” on the wound, which stops it from bleeding. That’s the blood clot.

If the lining of a blood vessel becomes damaged, cells called platelets are recruited to the injured area to form an initial plug. The platelets, in turn, release chemicals that start a cascade of events called the clotting cascade. In the end, a protein called fibrin crosslinks with itself to form a mesh that makes up the final blood clot.

This video makes it easier to understand:

Where can a blood clot form?

Anywhere there is a blood vessel:

1. On arteries – These are the vessels that carry blood from the heart to our organs.
2. On veins – These carry blood back from the organs to the heart.
3. In the heart itself

When do they happen?

1. On veins: Vein clots usually occur when a person becomes immobilized. Usually our muscles help pump blood back to the heart from the veins. When we don’t move, this doesn’t happen, causing blood to stagnant in the area and causing a tendency towards blood clot formation.
   Examples of such situations include being hospitalized or bedridden after illness or surgery. Also with long trips in a car or a plane, with orthopedic injuries and casting, and also in pregnancy. One other important reason is cancer, which raises your chance of having blood clots formed (which is probably why the girl on the House episode had a blood clot).

   Some people also have a genetic tendency towards clotting, putting them at much higher risk than the rest of the population for vein clotting.

   You can read about a condition that forms when clots form in your leg veins here:
   Deep vein thrombosis – Clots in Your veins which can travel to your heart and lungs

   
   Being immobile for a long time can lead to clots in your veins. Photo by Patrick Powers.

2. On arteries:
   Here the mechanism is different. A disease process causes plaques to accumulate along the lining of the artery. They grow and occlude the blood vessel, causing diseases like a heart attack and stroke. You can read further about this process here:
   Understanding heart attacks part 1 – Atherosclerosis
3. In the heart:
   When a condition called atrial fibrillation occurs (it’s a condition in which the heart beats and pumps blood in an irregular fashion) blood tends to become stagnant along the walls of the heart. This may lead to clot formation. Also when there is damage to the heart, such as after a heart attack, clots can form.

What can they cause?

The list is long. Blood clots can cause all sorts of conditions. Those in the veins can cause deep vein thrombosis (see the article linked above) and clots that prevent your lungs from doing their job (a condition called pulmonary embolism).

Those in the arteries can lead to heart attacks, strokes, and peripheral arterial disease.

Clots can be sent from the heart when they occur there. They can then block blood supply to all sorts of organs in the body, causing problems there: from damage to your intestines, kidneys, or even the brain (as was seen on the House episode).

How are clots discovered?

Besides symptoms caused by each of the conditions listed above, which doctors can identify, other means can help as well.

For example, a clot in the leg can be discovered using ultrasound. When it reaches the lung, methods like a CT scan of the chest can discover it. When a clot blocks blood supply to the heart, an EKG can discover that.

There are also blood tests which show that a clot was formed.

There are as many methods of detecting a clot as there are diseases caused by excessive clotting.

How are they treated?

That really depends on the condition they caused. For example, if a clot was formed in the lungs or legs, a blood thinner is used. If it was formed in the heart, a procedure called cardiac catheterization may be needed.

You can read about the various treatments for each condition in the links around this article leading to the condition’s page.

How can blood clots be prevented?

1. Arterial clots: To prevent those you have to minimize your risk factors (an explanation about each is given in our atherosclerosis article) – this means lowering your blood pressure and cholesterol, taking care of diabetes, and quitting smoking. Exercising regularly can also help a lot.
2. Vein clots: It’s important to move around to avoid being immobile and letting the clots happen. You can read the whole list of preventative measures in our article. They include, among others, walking while on a plane, moving as much as you can after a surgery, etc.

Related posts:

1. Deep Vein Thrombosis – Clots in Your Veins Which Can Travel To Your Heart and Lungs
2. Are Obese Kids at Risk for Heart Disease?
3. Lung Cancer – Why You May Be at Risk (As Seen on House MD)

This is part of our House MD Project series.

Episode 21 of season 1, named “Three Stories” is not a usual episode. Instead of the usual one patient story (and the occasional clinic patients), this episode tells 3 short stories (as its name implies). Each patient presented with a different disease. Since this episode was presented differently, so will this article digress from the usual presentation. The 3 diseases on that episode will be covered here in brief.

Disease 1 – Necrotizing Fasciitis

This long name means simply an infection by what is known as the “flesh eating bacteria”.

On the House episode, a 40 year-old farmer arrives at the hospital claiming he was bit by a snake. After an anti-venom doesn’t help him and his leg’s muscles begin to rot, it is found out he was actually bitten by a dog, a bite that infected him with a germ called streptococcus.

We already covered necrotizing fasciitis in the past and you can read all about this disease here:

Necrotizing Fasciitis (Flesh Eating Bacteria) – Are You at Risk, and How You Can Avoid It

Disease 2 – Osteosarcoma

update: We now have a complete article about osteosarcoma, if you’re interested to know more details

The 2nd patient is a 16 year-old volleyball player arriving at the hospital after what seems like a strained ankle. After some trial and error it is found she has osteosarcoma, a cancer in the leg of thigh.

Osteosarcomas are the most common malignant bone cancer in children (along with a cancer named Ewing sarcoma). The cause is unknown. In the US, about 400 children and adolescents younger than 20 years old are diagnosed with osteosarcoma each year. It most commonly affects adolescents.

The disease presents with pain in a bony site. A mass may be palpable in the area as well. X-ray image of the area can discover the tumor. A biopsy from the area is needed to make sure it’s osteosarcoma.

An x-ray picture of an osteosarcoma of the arm. Photo by bc the path

Before chemotherapy, osteosarcoma used to be treated with amputation alone. Today chemotherapy is used along with surgery which can cut the tumor. Sometimes amputation is still needed, as was seen on House.

Disease 3 – Aneurysm

The 3rd patient is actually Dr. House himself, telling the story of how he got his leg pain to begin with. Turns out he had an aneurysm in the artery of his leg which wasn’t diagnosed on time, leading to blockage of blood to his leg’s muscles, which led to muscle death.

An aneurysm is a dilatation of an artery. The chances of getting it increase with age (it happens to at least 3% of people older than 50). Most aneurysms don’t cause any symptoms and go unnoticed. As they progressively enlarge, though, they may cause symptoms as a result of compression of the surrounding area, of clogging, sending a blood clot, or rupturing.

In the case of the House episode, his leg aneurysm clogged with a blood clot. This led to blood not arriving to his leg muscles, causing muscle death.

Related posts:

1. Osteosarcoma–The Most Common Bone Cancer in Children (As Seen on House MD)
2. Necrotizing Fasciitis (Flesh Eating Bacteria) – Are You At Risk, and How Can You Avoid It
3. Acute Intermittent Porphyria Revisited (As Seen on House MD)

This is a guest post by Dr. Bhagat Reddy. Dr. Reddy is the Director of Vascular Medicine & Endovascular Interventions at Piedmont Heart Institute in Atlanta, Georgia.

Danger level: High

What is it?

Peripheral Arterial Disease (PAD) occurs when a patient’s blood vessels narrow over time as a result of several different factors pertaining to the build up of atherosclerotic or claudic materials. This can affect many major blood vessels supplying the organs and the limbs.

Who gets it?

Patients who have a history of high blood pressure, diabetes, high cholesterol, and smoking are particularly at risk. Also at risk are patients who have had blockages in other areas of the body or patients with a family history of conditions like heart disease or aneurysms. These are the most important risk factors patients should look for and physicians should screen for.

Of course, PAD is a disease with high correlations to advanced age. It does not matter if you are male or female, as you age you have an increased chance of developing it. The disease also appears to affect patients worldwide, including in Third World countries. In fact, it appears more quickly in patients in non-western regions due to high rates of smoking and diabetes in those countries, specifically India and China.

What causes it?

Over time, and for reasons we are continuing to understand today, PAD is caused by an accumulation and deposition of cholesterol in the lining of blood vessel walls. This can happen in any part of the body, whether the vessel is supplying a major organ like a kidney, the brain, the intestines or stomach, or even the upper and lower limbs. A lot of the risk factors mentioned above don’t just cause the problem but instigate and propagate the issue.

A normal artery and an artery with an accumulation of cholesterol in its lining.

How does it feel?

Symptoms usually depend on where the affected blood vessel is located.

Upper extremity – patients experience pain, fatigue, weakness, numbness, or difficulty using the arm. In some situations the patient may also notice instability in gait or difficulty walking in a straight line.

Lower extremity – If the blood vessel involved affects the lower limbs, the patient usually has pain in the buttocks, calf, or foot, depending upon the location and extent of the blockage. The patient might also experience fatigue, tiredness, weakness, or numbness either during exercise or at rest if the case is severe. Some important signs in patients with critical disease in the lower extremities, apart from severe pain, include non-healing sores, especially in patients with diabetes, and/or discoloration of their toes and foot (which would indicate gangrene).

Kidney – If the blood vessel to the kidney is involved, the disease is mostly silent and symptomless. However, patients may have early or late onset of hypertension and/or difficulty controlling blood pressure despite reasonable treatment with medications. Patients may also have an abnormal kidney function detected on routine blood tests.

Abdomen – If the blockage restricts blood flow to the belly, patients experience significant abdominal pain after eating and significant weight loss over time.

Neck/Brain – If the blockage restricts blood vessels supplying the neck or brain, patients usually exhibit stroke-like symptoms.

How is it discovered?

The best way to detect PAD, apart from asking questions about risk factors, is to examine the patient and feel pulses. Physicians should examine the patient with the stethoscope and listen for abnormal, “squishy” sounds that could indicate blockages in any part of the body. Next, an ABI, or Ankle Brachial Index, can be conducted to measure the blood pressure in the arms and the legs. Blood pressure is supposed to be equal in the arms and legs: if it’s lower in the legs, it means the patient could have reduced blood due to blockages. Clinical studies have shown that an abnormal ABI measurement, meaning lower blood pressure in the legs, is a sign of heart and vascular disease, and therefore also signifies a chance of early death due to these conditions.

How is it treated?

PAD is treated first and foremost by understanding, addressing and correcting risk factors for the disease, because if uncorrected, the disease continues to propagate in different areas of the body. So the treatment of hypertension, diabetes and smoking are important upfront. There are also certain medications designed to help reduce hypertension and cholesterol, such as aspirin and Plavix, that appear to significantly help these patients.

What is key is to not just recognize the problem, but to recognize the intensity and severity of the problem at the time. Based on a physician’s detailed examination, when severity is detected, the physician should focus on which part of the body needs priority in treatment by opening the blockages. Blockages are opened most of the time in a nonsurgical fashion using catheters or devices through a small needle stick.

Fortunately, we are able to provide most of the procedures on an outpatient basis without sedation. Patients do not need anesthesia and have a very quick recovery; plus, the chances of having major complications or infections is very low. The other significant advantage is that these procedures can be performed on a patient multiple times over a lifetime if additional blockages appear throughout the body.

What happens after treatment?

The outcome is fairly good for PAD patients, depending upon the extent and location of blockages. Outcome can also vary on a patient-to-patient basis. Most times, if the disease is treated effectively and the patient addresses and corrects risk factors with the help of a healthcare practitioner, the outcome appears to be very good. However, most patients will need to follow up with their vascular consultant for the rest of their lives, because this is a disease in progress. Even though the most serious problem has been fixed, a patient may develop a problem in another location in the body that could and should be treated before it proves serious. So – early detection and treatment should always be the priority.

The bottom line – How do I avoid it?

Most people, at least in the US, die of cardiovascular causes. It’s important to recognize this, because recognition and treatment of these patients is of significant value: if these patients are not treated, they will die much earlier than most people who do not have vascular disease.

People cannot necessarily avoid PAD, but they can be vigilant in early detection, treatment and managing risk factors. If a patient has already identified his/her risk factors, the next step is to aggressively continue toward improving or resolving the risk. Most importantly, patients need to be on the lookout for any vascular condition to get treated before it causes severe organ damage and/or death.

Related posts:

1. Behçet’s Disease – Inflammation of Your Blood Vessels, Throughout the Body (As Seen on House MD)
2. Wegener’s Granulomatosis–A Rare Inflammation in Blood Vessels that Can Lead to Death (As Seen on House MD)
3. Arteriovenous Malformation – The Blood Vessel Defect That Can Change Your Life (As Seen on House MD)

Danger level: High

What is it?

Temporal arteritis (also known as giant cell arteritis) is a disease in which there is an inflammation of your blood vessels (which in medical terms is called vasculitis). Most often it affects the arteries in our head.

Who gets it?

Temporal arteritis (TA) affects women about 2-3 as much as men. It’s usually seen after age 50 (90% of people with TA are over 60), and happens to 1-5 in 10,000 people.

It’s more common in white people, especially if their origin is northern European.

What causes it?

Vasculitis is a condition in which our blood vessels get inflamed, which damages them and causes various diseases. It can affect blood vessels of any size: small, medium and large.

In TA, medium and large sized arteries are involved. It is called “temporal arteritis” is it most commonly involves the superficial temporal arteries, located on our temples.

The superficial temporal artery (marked by a line above). It’s the artery most commonly involved in TA.

The disease’s other name, “giant cell arteritis”, means that it involves other medium and large arteries, including the aorta, carotid, subclavian and others.

No one knows for sure what causes the inflammation in these arteries.

How does it feel?

The most common symptom is a headache, and tenderness around the temples, where these arteries lie. The pulses in these arteries may vanish as well.

Other things which can be felt include:

• Jaw pain when you chew – This is called jaw claudication in medical language.
• Low grade fever – Meaning you have a fever, but it’s not too high (around 99.5F or 37.5C).
• Fatigue
• Weight loss
• Muscle pain
• Lack of appetite

One of the most feared things which can happen in this disease is the involvement of another nearby artery – the opthalmic artery. This artery sends blood to our eye nerves, and damage to it can cause blindness, which is why treating this disease on time is very important.

About half the people with TA also have a condition called polymyalgia rheumatica. It involves pain and stiffness in the neck, arms or hips. It’s usually worse in the morning before going out of bed.

How is it discovered?

There are two main things done to discover TA:

1. Blood tests – Two tests, called ESR and CRP hint at TA when they are high.
2. Biopsy – This is a procedure in which a piece of the temporal artery is taken and seen under a microscope to see if it is inflamed.

How is it treated?

The drug of choice to treat TA is steroids. Since the vision is threatened here, many doctors give these even before they are certain you have TA, to save your eye sight.

What happens after treatment?

Usually, if treated on time, the disease tends to go away. It may last up to 2 years.

There’s currently no known way to prevent TA.

Related posts:

1. Wegener’s Granulomatosis–A Rare Inflammation in Blood Vessels that Can Lead to Death (As Seen on House MD)
2. Blind Grandmother Recovers Sight With Implanted Tooth in Eye
3. Sickle Cell Disease – When the Shape of Your Blood Cells Can Kill You (As Seen On House MD)

Danger level: High

What is it?

The aorta is the largest blood vessel in our body, and it responsible for supplying blood to all of our organs. Aortic dissection is a life-threatening situation which occurs when a tear develops in the inner layer of the aorta.

Who gets it?

Aortic dissection is 3 times more common in men than in women. Mostly it tends to occur between the ages 40 and 70, with most cases occurring between ages 50-65.

Aortic dissection is more common in African Americans than in white people, and is even less common in people of Asian origin.

There are a few risk factors which put you at risk of having an aortic dissection:

1. High blood pressure – In more than 70% of the cases of aortic dissection, it happens to people with high blood pressure.
2. Diseases in the connective tissue – Connective tissue is a material of which certain things in our body are built, such as tendons, bones and cartilage. There are a few diseases that are specific to this tissue, including Marfan syndrome, Ehlers-Danlos and others. People with these conditions are at risk of having an aortic dissection.
3. Problems in the aorta from birth – There are all sorts of variations in the build of the aorta, with which we can be born (such as a bicuspid aortic valve and others). Having them puts you at risk of having a dissection.
4. Inflammation in your aorta – There are diseases which can cause this, including syphilis, Takayasu, Giant cell arteritis and Behcet’s disease.
5. Pregnancy – If it occurs during pregnancy, it is more common in the 3rd trimester.
6. Injury to the aorta – Such as during a motor vehicle accident.

What causes it?

Our blood vessels, including the aorta, are made of 3 layers. The innermost layer (the one in touch with the blood) is called the intima. The middle layer is called the media, and the outermost layer is called the adventitia.

In aortic dissection, a tear develops in the innermost layer – the intima. Blood enters through the tear, which causes the inner and middle layers to separate.

In an aortic dissection, there is a tear in the innermost layer, through which blood enters the middle layer. Drawing by J. Heuser.

After the blood enters between these two layers, there is a lot of pressure there, caused by the force of the blood flow. This can cause the split between the two layers to continue further down or up the aorta.

This video shows the process:

The tear which runs backwards or forwards along the aorta can cause tears in blood vessels coming out of the aorta and supplying organs in our body. This can lead to a heart attack if it gets to the blood vessels supplying the heart; a stroke, if the blood vessels supplying the brain are involved; kidney failure if it reaches the arteries supplying the kidney, and so on.

Besides that, the main risk in an aortic dissection is that the outer layer (the adventitia) will give way and tear, causing a massive blood loss and death.

How does it feel?

The main thing felt in aortic dissection is a sudden and severe chest pain. It feels as if you have been stabbed with a knife, and radiates to your back. The pain can be associated with cold sweat.

As the dissection gets worse, the pain tends to move with it.

How is it discovered?

There are a few things a doctor can do to discover if you have an aortic dissection:

1. X-rays or CT scans of the chest – They will show the problem in the aorta.
2. Echocardiography – This is an ultrasound of the heart and the area around it. It will also show if you have a dissection.

There are other methods as well, which are used less frequently to detect if you have a dissection.

How is it treated?

An aortic dissection is considered an emergency and requires an immediate treatment. According to the area in the aorta in which the tear occurred, there are two options for treating it:

1. Surgery – In the surgery, the problematic area is taken out, the tear area is blocked, and then a tube is inserted into the aorta – this “builds” the shape of the aorta again. The tube is called a graft.
2. Medications – These are drugs which take down the blood pressure, causing less stress in the area of the tear.

What happens after treatment?

About 20% of people with a dissection die before reaching the hospital. If not treated, the chances of dying from it are high.

After treatment many people will need to take medications to lower their blood pressure for the rest of their lives, in order to prevent this from happening again.

The bottom line – How do I avoid it?

The most important things is to lower your blood pressure if you have hypertension.

If you have any of the conditions mentioned above in the risk factors, you should consult your doctor on how to prevent a future dissection.

Also, when in a car, be sure to wear a seatbelt. This will reduce the risk of injury to your chest.

Related posts:

1. Migraine Headaches – How To Tell If Your Headaches Are Life Threatening, and What You Can Do About Them
2. 10 Screening Tests That Can Save Your Life
3. Peripheral Arterial Disease – A Narrowing of Blood Vessels that Will Shorten Your Life

Danger level: High

What is it?

Hypertension is an elevated level of the blood pressure, which can lead to serious complications.

Who gets it?

Hypertension affects about 60 million people in the US (30% of the population), and about 1 billion worldwide. It’s been estimated that hypertension is responsible for 6% of deaths worldwide.

The older you are, the more likely you are to have hypertension (after age 60, about 65% of the population has it).

There are certain risk factors which increase your risk of having a hypertension. These include:

1. Obesity – The more overweight your are, the more likely you are to get hypertension.
2. Eating foods rich in salt.
3. Having a family history of high blood pressure, heart disease or diabetes.
4. African American origin.
5. Being sedentary – Not doing any physical activity can raise your risk
6. Drinking alcohol excessively
7. Smoking
8. Using certain medications

What causes it?

First of all, what is a blood pressure?

It’s the force of blood pushing against our arteries as the blood flows through the body. You can understand it better if you think about a garden hose. As more water passes through the hose at a certain time, the more force works against the hose. This can damage the hose, or in real life, damage the blood vessels.

The reason for the development of hypertension in a person isn’t always known. Most of the time (95% of cases), the cause is unknown. In such cases, the condition is called essential hypertension.

The other, less common, type of hypertension is called secondary hypertension, since it’s secondary to other conditions. Causes here include Cushing’s syndrome, sleep apnea, drugs, kidney diseases, pheochromocytoma, thyroid problems and others (we will cover all of those in the future).

How does it feel?

That’s the main problem: Usually you don’t feel a hypertension. That’s why it’s been called “the silent killer” – you may walk around not knowing you have it until something happens.

That’s why regular checkup at your doctor’s office are important.

How is it discovered?

The doctor uses a cuff which they put around your arm to measure your blood pressure.

A blood pressure cuff.

When measured, the blood pressure appears as 2 numbers: The first (and higher) one is called the systolic blood pressure (this is the pressure that is measured when the heart beats and fills the arteries with blood). The second one is called the diastolic blood pressure (the pressure that’s measured when the heart rests between beats).

Generally speaking, when you have a blood pressure reading of 140/90 or higher (taken at least twice) you are said to have a high blood pressure.

How is it treated?

Treating a high blood pressure contains a few stages:

First – Modifying your lifestyle

Before starting with drugs, hypertension is usually treated first with lifestyle modifications. These include:

1. Weight loss – In people who are overweight or obese.
2. Starting a healthy diet – The diet recommended for people with hypertension is called the DASH diet (short for Dietary Approaches to Stop Hypertension). This diet is rich in fruits, vegetables and low-fat dairy products, with reduced fats.
3. Taking off salts in your diet
4. Physical activity
5. Drinking less alcohol

Each of these things can contribute to lowering your blood pressure. If that’s not enough, the next step follows.

Second – Medications

There are many types of drugs to treat hypertension, and they are beyond the scope of this article. Your doctor will recommend which ones to start with, and what drugs to add if the first one doesn’t do the trick.

What happens after treatment?

If the blood pressure is treated, everything is fine and dandy. The problem is, a lot of people don’t stick to their pills. Like we said above – you don’t feel hypertension, so why should you stick with those pills (and their side effects)?

Which takes us to the “silent killer” part. Untreated, hypertension can cause damage to organs in our body:

1. The heart – Hypertension can lead to atherosclerosis and heart attacks.
2. The brain – Hypertension can lead to strokes, especially those caused by bleeding to the brain.
3. The kidneys – Hypertension can lead to kidney failure.

Yes, 30% of the population has a high blood pressure. It doesn’t mean that YOU have to be one of them. There are certain things you can do today to lower your risk of developing hypertension:

1. Maintaining a normal weight – Your target BMI should be 18.5 to 24.9 (for explanations about that and for a starter’s guide for losing weight, you can visit our article about using the Internet to lose weight).
2. Reducing salt in your diet – The nutrition labels on foods you buy can help you. You should aim at less than 2,300mg of sodium (salt) a day. This is the equivalent of about 1 teaspoon of salt.
3. Exercising – For at least 30 minutes on most days of the week.
4. Limiting your alcohol intake – To 2 drinks a day if you’re a man or 1 if you’re a woman.
5. Following the DASH diet

This video sums it up (it talks mostly about Canada, but applies to every country) -

Got any tips of your own? Share them in the comments.

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Danger level: High

What is it?

Deep vein thrombosis (DVT for short) is a blood clot (or thrombus in Greek) that forms in a deep vein in the body.

Who gets it?

There are a few risk factors for developing DVT:

1. Conditions that cause the blood to move slower– For example if you are bedridden for a long time or paralyzed, or if you sit in an airplane for a prolonged time (usually for more than 8 hours).
2. Injury to our blood vessels: This can happen after a trauma or after a major surgery (such as orthopedic surgeries).
3. A propensity for clotting – In some people, clots can form more commonly than in others. This includes people with blood disorders which can cause this, as well as women taking contraceptive pills (and those taking hormones after menopause), and it can also happen after taking other types of drugs.
4. Cancer – Can raise your risk of developing DVT.
5. Pregnancy
6. People who have had it before – Are more prone to developing DVT again.

Oral contraceptive pills. They can cause DVT. Photo by Gnarls Monkey.

What causes it?

Our body has a clotting system. This is the system that’s responsible for the clot that forms when you are wounded. Platelets (a type of blood cell) in our blood aggregate in the area of the wound, and along with other materials in the blood form the clot. Usually in our body there is a balance between the system that forms clots and systems that prevent clots from happening or dissolve them when they do.

In DVT, as a result of the risk factors above, the clotting system works more than the systems which prevent or melt clots, which causes the clot to form inside the blood vessel.

A blood clot inside a vein.

How does it feel?

Clots form mostly in the veins of the legs or in the pelvis (the hip area). Less commonly, they can form in our arms.

As a result of the clot, the leg gets swollen, and may feel warm and look redder than the other leg. It can also hurt or be tender to touch.

You can see above that this disease is tagged as danger: high. If all it does is pain in the leg, you might ask yourself what’s so dangerous. The danger is that these clots can break loose from their original location, travel through the bloodstream to the lungs, and block the blood flow in the lungs (a condition called pulmonary embolism). This is life threatening.

Other than that, DVT can damage the veins in the leg in the long run (a condition called chronic venous insufficiency).

How is it discovered?

There are a few ways to discover DVT:

1. An ultrasound of the legs – It can detect the blood flow in the legs and show if it’s blocked by the clot.
2. A blood test – Which can discover if you have DVT (the test is called D-Dimer).
3. Venography – This is an X-ray picture of the blood flow through your veins.

How is it treated?

There are 2 ways to treat DVT:

1. Above we mentioned that as well as the system in our body which is responsible for clotting, there are systems responsible for stopping the clotting process and for dissolving the clots.

   There are drugs which help these other systems. These drugs are called blood thinners (or in their medical name, anticoagulants). Examples of such drugs are heparin and warfarin. These drugs are usually given for at least a few months until you are out of risk (and if you have a permanent condition which makes your blood clot, you may have to take it for life).

2. Inferior vena cava (IVC) filter – There are people who can’t get blood thinners, and there are also people who still get DVTs although they take these drugs. For these people, a type of filter is inserted into our vena cava, which is a vein in which the blood travels from the lower body to the heart. Putting the filter there prevents clots from reaching the heart and the lungs.

What happens after treatment?

Treating this condition on time prevents its complications (pulmonary embolism and venous insufficiency).

The bottom line – How do I avoid it?

There are a few things you can do to prevent DVT:

1. On long flights – Some doctors recommend that you wear compression stockings (they’re available at medical supply stores) during the flight. On long flights you should walk up and down the aisle hourly (working your leg muscles squeezes the veins and moves the blood in them), drink plenty of water (since dehydration, which is more common when you’re on an airplane, can make your blood thicker and drive clot formation), flex and point your feet occasionally, and avoid alcohol and drinks which contain caffeine (since they contribute to dehydration).

   This also applies to long travels by car, when you sit most of the time.

2. If you have a family history of blood clotting, inform your doctor – This can potentially prevent conditions which run in families and cause blood clotting from putting you at risk for DVT.
3. When you undergo a surgery or when bedridden – You will be given medications and other measures to prevent DVT from occurring.

This video sums it up:

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Danger level: High

What is it?

Kawasaki is a disease that causes inflammation of blood vessels.

Who gets it?

Kawasaki is mostly a children’s disease, and occurs mostly between the ages 1 and 8. 80% of cases occur before age 4.

Kawasaki is most common in children of Japanese descent, but can happen to others as well. It’s more common in boys than girls.

What causes it?

In Kawasaki there’s an inflammation of blood vessels. Since in medicine an inflammation’s name usually contains “is” in the end, inflammation of blood vessels is called a vasculitis.

Our arteries, much like shirts, come in 3 sizes: Large, medium and small. There are many types of vasculitis, with each affecting different artery sizes. Kawasaki is an inflammation of medium sized arteries. Our coronary arteries (the arteries that run on our heart and supply it with oxygen) are also involved here, putting the heart in danger.

Our heart and the coronary arteries that run on it. They’re in danger in Kawasaki disease.

No one knows why, but in Kawasaki the body attacks the blood vessels by the immune system, which is usually responsible for attacking infections (a process which is called auto-immune. We covered other auto-immune diseases here in the past, such as Hashimoto, Myasthenia Gravis, Vitiligo and Graves disease).

How does it feel?

There are a few things that happen in this disease:

1. Fever – This is the most characteristic sign. There’s a fever here that persists for 5 days or more.
2. Red eyes – This usually starts within 1-2 days after the fever begins.
3. A body rash
4. Swollen, red lips and tongue – The tongue here looks like a strawberry, and so is called a “strawberry tongue”.
5. Swollen, red feet and hands – Which later undergo desquamation (peeling of the skin, like in a snake).
6. Swollen lymph nodes in the neck

Other things that might occur are joint pain, a rapid heart beat and other things.

Since the heart can be involved in the disease, about 1-4 weeks after it begins, symptoms related to the heart can occur. Examples of these include failure of the heart to function properly, heart rhythm problems, inflammation of the heart and more.

The most feared complication in the heart is an aneurysm in the coronary arteries, which means a widening of the artery. This can leas to serious complications.

Recently Kawasaki disease was brought to the headlines after the death of John Travolta’s son, Jett, but it was later claimed that his death did not have anything to do with the disease.

This video shows the story of Nicky O’Donnell, a kid who was diagnosed with Kawasaki, a diagnosis which saved his life:

How is it discovered?

There is no lab test that can confirm the presence of Kawasaki disease, and the diagnosis is made by recognizing the above symptoms.

Also, an EKG and a heart imaging (echocardiogram) will be done to see the state of the heart and rule out any complications as a result of the disease.

How is it treated?

The treatment of Kawasaki can includes two things:

1. IVIG – These are immunoglobulins, or molecules that are given through the veins, which help to reduce the inflammation of the blood vessels.
2. Aspirin – It lowers the risk of blood clots, which can form here. (Please note: Aspirin is usually not recommended for children since it can cause a condition called Reye’s Syndrome. Kawasaki is about the only disease when it is given to them).

Blood thinners may also be required.

What happens after treatment?

Most children get better and have no long-term effects. About 20% of people who are not treated will have problems with their coronary arteries, which in rare cases can even lead to a heart attack.

The bottom line – How do I avoid it?

There is no known way to prevent Kawasaki disease from occurring.

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3. Understanding Heart Attacks – Part 3 – Myocardial Infarction