Many people with essential thrombocythemia have no signs or symptoms. The first indication you have the disorder may be the development of a blood clot (thrombus). Although clots can develop anywhere in your body, with essential thrombocythemia, they occur most often in your brain, hands and feet.

Signs and symptoms depend on where the clot forms. They include:

  • Headache
  • Dizziness or lightheadedness
  • Chest pain
  • Weakness
  • Fainting
  • Temporary vision changes
  • Numbness or tingling of the hands and feet
  • Redness, throbbing and burning pain in the hands and feet (erythromelalgia)
  • Mildly enlarged spleen

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:

  • Nosebleeds
  • Bruising
  • Bleeding from your mouth or gums
  • Bloody stool

A blood clot may cause a transient ischemic attack (TIA) — a temporary interruption of blood flow to part of the brain — or stroke. Signs and symptoms 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

If you have any signs or symptoms of abnormal blood clotting or bleeding, see your doctor.

If you develop signs or symptoms of a TIA or stroke, such as numbness or paralysis on one side of your body, seek medical attention immediately.

Sep. 22, 2012