Essential Thrombocythemia (ET)

What is essential thrombocythemia? 

Essential thrombocythemia (ET) is a rare blood disorder that sees the body create an excess of platelets. This excess increases the risk of blood clots. Those over the age of 50 are at a higher risk for this disorder, and research has found that females are at a slightly higher risk as well. 

What are the symptoms of essential thrombocythemia?

Symptoms can range from mild to severe, depending on the affected individual. Some may not even notice the effects.

The most common symptom is blood clots, and they typically occur in the hands, feet, and brain. Other symptoms will occur because of these clots, and those include fatigue, dizziness, headaches, temporary changes in vision, fainting, tingling and numb hands and feet, and redness, throbbing, and pain in the hands and feet. 

In severe cases, bleeding may occur. This may happen as nosebleeds, bleeding from the mouth and gums, easy bruising, and blood in the stool. 

This disorder can be very dangerous if clotting occurs in the arteries of the brain. People may experience strokes or transient ischemic attacks (TIAs), also referred to as ministrokes. These symptoms include weakness or numbness on one side of the body, changes in vision, and aphasia. 

While strokes are a main complication of this disorder, there are others. These include heart attacks, excessive bleeding, and the progression of ET into acute myeloid leukemia or myelofibrosis. 

What causes essential thrombocythemia?

ET falls under the larger category of chronic myeloproliferative disorder. This type of disorder sees the bone marrow create an excess of one type of cell, and in this case it is platelets. 

Medical professionals are unsure as to why this disorder happens, but they have found that around 90% of those with ET have an inherited genetic mutation that contributes. 

How is essential thrombocythemia diagnosed?

Doctors will take blood counts to diagnose ET. If one’s blood count is above 450,000 platelets, doctors will begin to look for the cause. They will rule out other conditions before coming to a diagnosis of ET. Doctors may use blood and bone marrow tests. 

What are the treatments for essential thrombocythemia?

There is no cure for this condition, but there are many treatments. For some, treatment may not even be necessary. Those who are young and asymptomatic may only require regular checkups. 

For those who do require treatment, doctors will prescribe medication that reduces the platelet count and lowers the clotting risk. In case of an emergency, such as a stroke, doctors will use a platelet pheresis to temporarily lower the platelet count.  

Where can I find out more about essential thrombocythemia?

• • Mayo Clinic
  • NIH
  • NORD