Thrombocytopenia is a medical condition characterized by a low platelet count in the blood. Platelets are small cells in the blood that help with clotting and stopping bleeding. Thrombocytopenia can be caused by a variety of factors, including certain medications, infections, autoimmune disorders, and genetic conditions. Symptoms of thrombocytopenia can include easy bruising, prolonged bleeding from cuts, and excessive bleeding from minor injuries. Treatment for thrombocytopenia may include medications to increase platelet production, transfusions of platelets, or addressing the underlying cause of the condition.