Bone marrow — spongy tissue inside your bones — contains stem cells that can become red blood cells, white blood cells or platelets (thrombocytes). Platelets stick together, helping blood to form a clot that stops 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.
If you have thrombocytosis caused by a bone marrow disorder (essential thrombocythemia), your bone marrow overproduces the cells that form platelets (megakaryocytes), releasing too many platelets into your blood. In essential thrombocythemia, there is a much higher risk of clotting or bleeding complications. Therefore, if your blood test results reveal a high platelet count, it's important for your doctor to determine whether you have essential thrombocythemia or reactive thrombocytosis.
Reactive thrombocytosis causes include:
- Acute bleeding and blood loss
- Allergic reactions
- Chronic kidney failure or another kidney disorder
- Heart attack
- Coronary artery bypass
- Infections, including tuberculosis
- Iron deficiency
- Vitamin deficiency
- Removal of your spleen
- Hemolytic anemia — a type of anemia in which your body destroys red blood cells faster than it produces them, often due to certain blood diseases or autoimmune disorders
- Inflammation, such as from rheumatoid arthritis, celiac disease, connective tissue disorders or inflammatory bowel disease
- Major surgery
Medications that can cause reactive thrombocytosis include:
July 10, 2015
- Epinephrine (AUVI-Q, EpiPen, others)
- Tretinoin (Retin-A, Renova, others)
- Vincristine Sulfate (Marqibo Kit)
- Heparin sodium
- Tefferi A. Approach to the patient with thrombocytosis. http://www.uptodate.com/home. Accessed June 15, 2015.
- What are thrombocythemia and thrombocytosis? National Heart, Lung, and Blood Institute. http://www.nhlbi.nih.gov/health/health-topics/topics/thrm/. Accessed June 15, 2015.
- Reactive thrombocytosis. Merck Manual Professional Edition. http://www.merckmanuals.com/professional/hematology-and-oncology/myeloproliferative-disorders/reactive-thrombocytosis-secondary-thrombocythemia. Accessed June 16, 2015.
- Sulai NH, et al. Why does my patient have thrombocytosis? Hematology/Oncology Clinics of North America. 2012;26:285.
- Kitchens CS, et al. Thrombocytosis. In: Consultative Hemostasis and Thrombosis. 3rd ed. Philadelphia, Pa.: Saunders Elsevier; 2013. http://www.clinicalkey.com. Accessed June 16, 2015.
- Mesa RA (expert opinion). Mayo Clinic, Phoenix/Scottsdale, Ariz. June 22, 2015.