Low platelets (thrombocytopenia)

Chest | Hematology | Low platelets (thrombocytopenia) (Disease)


Thrombocytopenia is the medical term for a low blood platelet count. Platelets (thrombocytes) are colorless blood cells that play an important role in blood clotting. Platelets stop blood loss by clumping and forming plugs in blood vessel holes.

Causes and Risk factors

Thrombocytopenia often occurs as a result of a separate disorder, such as leukemia or an immune system problem, or as a medication side effect. Thrombocytopenia may be mild and cause few signs or symptoms. In rare cases, the number of platelets may be so low that dangerous internal bleeding can occur. Under normal circumstances, the resistance of the endothelial cell lining to interactions with platelets and coagulation factors prevents thrombosis. When endothelial continuity is disrupted and the underlying matrix is exposed, a coordinated series of events are set in motion to seal the defect (primary hemostasis).

Diagnosis and Treatment

Thrombocytopenia usually improves when the underlying cause is treated. Sometimes medications, surgery or a blood transfusion can help treat chronic thrombocytopenia. The hemostatic system consists of platelets, coagulation factors, and the endothelial cells lining the blood vessels. The platelets arise from the fragmentation of the cytoplasm megakaryocytes in the bone marrow and circulate in blood as disc-shaped anucleate particles.