Effects of a high blood platelet count, or thrombocytosis, can include stroke, heart attack and blood clots due to blood vessel blockage, according to the Cleveland Clinic. After thrombocytosis has been in an individual's system for years, the bone marrow sometimes scars. In a few people, leukemia arises from thrombocytosis.
Thrombocytosis does not always cause symptoms, but some people can experience skin bruising or bleeding from the nose, mouth, gums, stomach or intestines. Most symptoms of Thrombocytosis, including fainting, headache, dizziness and vision problems, are due to the underlying conditions, states Mayo Clinic. Some people feel weak, have chest pains or lose sensations in their hands or feet.
Abnormal bone marrow cells increase platelet count in primary or essential thrombocytosis, Cleveland Clinic discloses. Patients typically go on long-term drug therapy to stops marrow from manufacturing so many platelets. If essential thrombocytosis becomes dangerous, a doctor performs a complicated procedure to remove excessive platelets from the blood.
In secondary thrombocytosis, other conditions, such as cancer, anemia, infection or spleen removal, cause high platelet count, according to the Cleveland Clinic. In these cases, doctors deal with thrombocytosis by addressing the underlying concerns. Aspirin is sometimes prescribed to prevent blood clots, although clots seldom happen with secondary thrombocytosis, observes Mayo Clinic. Once the source of the problem is addressed, the platelet count lowers to an acceptable level.