Thrombocytopenia is any disorder in which there is an abnormally low amount of platelets. Platelets are parts of the blood that help blood to clot. This condition is sometimes associated with abnormal bleeding.
Causes, incidence, and risk factors
Thrombocytopenia is often divided into three major causes of low platelets:
- Not enough platelets are made in the bone marrow
- Increased breakdown of platelets in the bloodstream
- Increased breakdown of platelets in the spleen or liver
Your bone marrow may not make enough platelets if you have:
- Aplastic anemia
- Cancer in the bone marrow such as leukemia
- Cirrhosis (liver scarring)
- Folate deficiency
- Infections in the bone marrow (very rare)
- Vitamin B12 deficiency
Use of certain drugs may also lead to a low production of platelets in the bone marrow. The most common example is chemotherapy treatment.
The following health conditions cause increased breakdown of platelets:
- Disseminated intravascular coagulation (DIC)
- Drug-induced nonimmune thrombocytopenia
- Drug-induced immune thrombocytopenia
- Immune thrombocytopenic purpura (ITP)
- Thrombotic thrombocytopenic purpura
You may not have any symptoms. General symptoms include:
- Bleeding in the mouth and gums
- Rash (pinpoint red spots called petechia)
Other symptoms depend on the cause.
Signs and tests
Your health care provider will perform a physical exam and ask questions about your medical history and symptoms. The following tests may be done:
- Complete blood count (CBC)
- Blood clotting studies (PTT and PT)
Other tests that may help diagnose this condition include:
- Bone marrow aspiration or biopsy
- Platelet associated antibodies
Treatment depends on the cause of the condition. In some cases, a transfusion of platelets may be required to stop or prevent bleeding.
The outcome depends on the disorder causing the low platelet counts.
Severe bleeding (hemorrhage) is the main complication. Bleeding may occur in the brain or gastrointestinal tract.
Calling your health care provider
Call your healthcare provider if you experience unexplained bleeding or bruising.
Prevention depends on the specific cause.
McMillan R. Hemorrhagic disorders: abnormalities of platelet and vascular function. In: Goldman L, Ausiello D, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 175.