Essential thrombocythemia (throm-boe-sie-THEE-me-uh) is an uncommon disorder in which your body produces too many platelets. Platelets are the part of your blood that sticks together to form clots.
This condition may cause you to feel fatigued and lightheaded and to experience headaches and vision changes. It also increases your risk of blood clots.
Essential thrombocythemia is more common in people over age 60, though younger people can develop it too. It's also more common in women.
Essential thrombocythemia is a chronic disease with no cure. If you have a mild form of the disease, you may not need treatment. If you have severe symptoms, you may need medicine that lowers your platelet count, blood thinners or both.
You may not have any noticeable symptoms of essential thrombocythemia. The first indication you have the disorder may be the development of a blood clot. Clots can develop anywhere in your body, but with essential thrombocythemia they occur most often in your brain, hands and feet.
Signs and symptoms depend on where the clot forms. They include:
- Dizziness or lightheadedness
- Chest pain
- Temporary vision changes
- Numbness or tingling of the hands and feet
- Redness, throbbing and burning pain in the hands and feet
Less commonly, essential thrombocythemia may cause bleeding, especially if your platelet count is more than 1 million platelets per microliter of blood. Bleeding may take the form of:
- Bleeding from your mouth or gums
- Bloody stool
Essential thrombocythemia is a type of chronic myeloproliferative disorder. That means your bone marrow, the spongy tissue inside your bones, makes too many of a certain type of cell. In the case of essential thrombocythemia, the bone marrow makes too many cells that create platelets.
It's not clear what causes this to happen. About 90% of people with the disorder have a gene mutation contributing to the disease.
If an underlying condition such as an infection or iron deficiency causes a high platelet count, it's called secondary thrombocytosis. Compared with essential thrombocythemia, secondary thrombocytosis causes less risk of blood clots and bleeding.
Essential thrombocythemia can lead to a variety of potentially life-threatening complications.
Strokes and mini-strokes
If a blood clot occurs in the arteries that supply the brain, it may cause a stroke or a transient ischemic attack (TIA). A TIA (mini-stroke) is a temporary interruption of blood flow to part of the brain.
Signs and symptoms of both a stroke and a TIA develop suddenly and include:
- Weakness or numbness of your face, arm or leg, usually on one side of your body
- Difficulty speaking or understanding speech
- Blurred, double or decreased vision
Seek medical attention immediately if you develop signs or symptoms of a stroke.
Less commonly, essential thrombocythemia can cause clots in the arteries that supply blood to your heart. Signs and symptoms of a heart attack include:
- Pressure, fullness or a squeezing pain in the center of your chest lasting more than a few minutes
- Pain extending to your shoulder, arm, back, teeth or jaw
- Shortness of breath
- Sweating or clammy skin
Seek medical attention immediately if you develop signs or symptoms of a heart attack.
Bone marrow problems, including leukemia
Rarely, essential thrombocythemia may progress to these potentially life-threatening diseases:
- Acute myelogenous leukemia. This is a type of white blood cell and bone marrow cancer that progresses rapidly.
- Myelofibrosis. This progressive disorder results in bone marrow scarring, leading to severe anemia and enlargement of your liver and spleen.
Most women who have essential thrombocythemia have normal, healthy pregnancies. But uncontrolled thrombocythemia can lead to miscarriage and other complications. Your risk of complications may be reduced with regular checkups and medication, so be sure to have your doctor regularly monitor your condition.
If your blood count is above 450,000 platelets per microliter of blood, your doctor will look for an underlying condition. He or she will rule out all other causes of high platelet counts to confirm a diagnosis of essential thrombocythemia.
Samples of your blood will be checked for:
- The number of platelets
- The size of your platelets
- Specific genetic flaws, such as the JAK2, CALR or MPL gene mutation
- Iron levels
- Markers of inflammation
Bone marrow tests
Your doctor may also suggest two bone marrow tests:
- Bone marrow aspiration. Your doctor extracts a small amount of your liquid bone marrow through a needle. The sample is examined under a microscope for abnormal cells.
- Bone marrow biopsy. Your doctor takes a sample of solid bone marrow tissue through a needle. The sample is examined under a microscope to determine whether your bone marrow has a higher than normal number of the large cells that make platelets.
Although there's no cure for essential thrombocythemia, treatments can control symptoms and reduce the risk of complications. Life span is expected to be normal despite the disease.
Treatment of essential thrombocythemia depends on your risk of blood clots or bleeding episodes. If you're younger than 60 and have had no signs or symptoms, you may simply need periodic medical checkups.
Your doctor may prescribe medication if:
- You're older than 60 and have had previous blood clots or TIAs
- You have cardiovascular risk factors, such as high cholesterol, high blood pressure and diabetes
Your doctor may suggest one of the following prescription drugs, perhaps along with low-dose aspirin, to reduce your platelet count:
- Hydroxyurea (Droxia, Hydrea.) This drug is the most common prescription used for essential thrombocythemia. Side effects may include nausea, hair loss, discolored nails, and ulcers in the mouth or on the legs. Long-term use may slightly increase the risk of developing acute myelogenous leukemia. But the disease itself increases the risk of leukemia, so it's difficult to determine the exact impact of hydroxyurea.
- Anagrelide (Agrylin). Unlike hydroxyurea, anagrelide isn't associated with an increased risk of leukemia, but it's not considered as effective. Side effects may include fluid retention, heart problems, headaches, dizziness, nausea and diarrhea.
- Interferon alfa-2b (Intron A) or peginterferon alfa-2a (Pegasys). These drugs are given by injection, and may cause worse side effects than hydroxyurea or anagrelide does. But it's the best choice for some people. Side effects may include flu-like symptoms, confusion, nausea, depression, diarrhea, seizures, irritability and sleepiness.
A medical procedure called plateletpheresis is used only in emergencies, such as after a stroke or other dangerous blood clotting. It involves passing your blood through a device that removes platelets and then returns the blood to your body. This temporarily lowers your platelet count.
Lifestyle and home remedies
If you have essential thrombocythemia, your doctor may recommend that you regularly take low-dose aspirin. Aspirin makes platelets less sticky and your blood less likely to form clots. If you're also pregnant, aspirin has a low risk of causing side effects to the fetus.
Also try to choose healthy lifestyle habits to lower your risk of developing conditions that may contribute to blood clotting. These include diabetes, high blood pressure and high blood cholesterol. Take steps to:
- Eat healthy foods. Choose a varied diet rich in whole grains, vegetables and fruits, and low in saturated fats. Try to avoid trans fats. Learn about portion control to maintain a normal weight.
- Increase your physical activity. Aim for at least 30 minutes of moderate physical activity a day. Take a brisk daily walk, ride your bike or swim laps.
- Stop smoking. Smoking increases your risk of blood clots. If you smoke, take steps to stop.
Preparing for an appointment
Here's some information to help you get ready for your appointment and to know what to expect from your doctor.
What you can do
- Be aware of any pre-appointment restrictions. At the time you make the appointment, ask if there's anything you need to do in advance, such as restrict your diet.
- List any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
- List key elements of your health history, such as blood clots, bleeding incidents and a family history of high platelet counts.
- List key personal information, including any major stresses or recent life changes.
- Make a list of all medications, vitamins and supplements that you're taking. Some medications, such as birth control pills, can increase the risk of blood clots in people with essential thrombocythemia.
- Take a family member or friend along. Sometimes it can be difficult to take in all the information you hear during an appointment. Someone who accompanies you may remember something that you missed or forgot.
- List questions to ask your doctor.
For essential thrombocythemia, some basic questions to ask your doctor include:
- What kinds of tests do I need?
- Is my condition temporary or long lasting?
- What treatment do you recommend for me?
- Will I have any side effects from the treatment?
- What kind of follow-up will I need?
- Do I need to restrict my activity?
- What are possible complications of my condition?
- I have other health conditions. How can I best manage these conditions together?
- Where can I find additional information on essential thrombocythemia?
Don't hesitate to ask other questions that occur to you during your appointment.
What to expect from your doctor
Your doctor is likely to ask you a number of questions, such as:
- What signs and symptoms have you noticed?
- When did you first notice these signs and symptoms?
- Have they gotten worse over time?
- Have you had a recent medical procedure or blood transfusion?
- Have you had a recent infection or vaccine?
- Do you drink alcohol?
- Do you have headaches, dizziness or weakness?
- Do you have any chest pain?
- Have you had any vision problems?
- Have you had any bleeding or bruising?
- Have you experienced any numbness or tingling in your hands or feet?
- Have you experienced any redness, throbbing or burning pain in your hands or feet?
- Do you have a family history of high platelet counts?