Essential thrombocythemia is an uncommon disorder in which your body produces too many blood platelets. 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 (throm-boe-sie-THEE-me-uh) is more common in people over age 50, though younger people can develop it too. It's somewhat 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 a severe condition, 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 (thrombus). 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 (erythromelalgia)
Less commonly, essential thrombocythemia may cause bleeding, especially if your platelet count is extremely high (more than 1 million platelets per microliter of blood). Bleeding may take the form of:
- Bleeding from your mouth or gums
- Bloody stool
If a blood clot occurs in the arteries that supply the brain, it may cause a transient ischemic attack (TIA) or stroke. A TIA, or ministroke, is a temporary interruption of blood flow to part of the brain. Signs and symptoms of a stroke or 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 (aphasia)>
- Blurred, double or decreased vision
When to see a doctor
Seek medical attention immediately:
- If you develop signs or symptoms of a TIA or stroke, such as numbness or paralysis on one side of your body
- If you develop signs or symptoms of a heart attack, such as 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; and sweating or clammy skin.
- If you have any signs or symptoms of abnormal blood clotting or bleeding
Essential thrombocythemia is a type of chronic myeloproliferative disorder. That means the 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 percent of people with the disorder have an acquired gene mutation contributing to the disease.
Platelets stick together to help form blood clots. Normally, blood clots stop bleeding when you damage a blood vessel, such as when you get a cut.
A normal platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. Someone with essential thrombocythemia has more than 450,000 platelets per microliter of blood.
Plus, the excess platelets may not function normally, leading to abnormal clotting or bleeding.
If an underlying condition such as an infection or iron deficiency causes a high platelet count, it's called reactive, or secondary, thrombocythemia. Secondary thrombocythemia causes less risk of blood clots and bleeding than does essential thrombocythemia.
Older people with essential thrombocythemia are at risk of complications. People who've had prior blood clots or bleeding problems related to the disease are also at risk of complications.
The abnormal blood clotting of essential thrombocythemia can lead to a variety of potentially serious complications, including:
- Stroke. A clot that blocks blood flow to your brain can cause a stroke. If you develop signs and symptoms of a stroke, get immediate medical attention.
- Heart attack. Blood clots that obstruct blood flow to your heart cause heart attacks. Get immediate attention if you develop signs and symptoms of a heart attack.
- Excessive bleeding. This may appear as nosebleeds, bleeding gums or bruising.
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.
Pregnant women with essential thrombocythemia have a higher risk of complications than women without the condition. But most women who have thrombocythemia have normal, healthy pregnancies.
However, 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
- The activity 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 (megakaryocytes).
Although there's no cure for essential thrombocythemia, there are treatments available. And, lifespan is expected to be normal despite the disease.
Treatment of essential thrombocythemia depends on your risk of blood-clotting 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 or clotting risk:
Hydroxyurea (Droxia, Hydrea). This drug suppresses bone marrow production of blood cells, including platelets. Its side effects are usually mild, and may include nausea, hair loss, discolored nails and ulcers in the mouth or on the legs.
Your doctor will monitor your blood counts and liver function. There's some concern that long-term use may slightly increase the risk of developing acute myelogenous leukemia.
- 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 (Intron A) or peginterferon alpha-2a (Pegasys). This drug is 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 platelet pheresis is used only in emergencies, such as after a stroke or other dangerous blood clotting. It temporarily lowers your platelet count. A needle connected to a tube allows your blood to flow into a device that removes platelets, after which your blood is returned to your body.
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. It's often used in pregnancy because it 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.
- Achieve or maintain normal weight. Being overweight or obese increases the risk of blood clots.
- Stop smoking. If you smoke, take steps to try to stop.
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 oral contraceptives, can increase the risk of blood clots in women 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 thrombocytopenia?
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?