Signs and Symptoms
The severity of an MPN varies from person to person. The condition may be acute and life-threatening or it may be very subtle, existing for years before being diagnosed, frequently during a routine physical. While each condition has its own set of symptoms, some symptoms are common to more than one. They include:
- Weight loss
- Weakness and fatigue
- Enlargement of the spleen (splenomegaly) - cells accumulate in the spleen because it makes blood cells and because it filters old or abnormal cells out of the bloodstream; this causes the spleen to swell, which can cause abdominal discomfort.
- Bleeding and bruising, due to insufficient and/or abnormal platelets
- Night sweats
- Bone and joint pain
- Pallor due to anemia (when red blood cells are decreased, not increased)
- Frequent infections
- Headache, dizziness, numbness and/or visual disturbance due to thicker blood or inappropriate clotting
In someone with polycythemia vera, the excess number of RBCs produced increases the volume and thickness (viscosity) of the blood. This can cause symptoms such as headaches, dizziness, visual distortion, itching, and paresthesia. Sometimes the excessive RBCs may lead to complications, such as stomach ulcers, kidney stones, venous thrombosis, stroke, and rarely to congestive heart failure.
People with polycythemia vera or primary thrombocythemia, especially if they are older than 60, may have disease progression and develop myelofibrosis, in which fibrous scar tissue replaces bone marrow that is similar to that seen in primary myelofibrosis. It often causes no symptoms early in the course of the disease; about one-third of those who are diagnosed are asymptomatic. People who do have symptoms may experience fatigue, shortness of breath, and splenomegaly. Fibrous tissue eventually fills the bone marrow, reducing the production of all blood cells. Anemia may become severe.
Most people with essential thrombocythemia are asymptomatic, but some develop thrombosis or hemorrhage because of increased numbers of dysfunctional platelets. This may cause tingling in the hands and feet, headaches, weakness, dizziness, nosebleeds, and easy bruising.