Platelets are the tiny, colorless blood cells that help blood form clots and stop bleeding from injuries. Thrombocytopenia, or low platelet count, can be caused by some chemotherapy medications and radiation therapy. When platelets are low, even small cuts, bumps, or injuries can be very serious because the blood does not have the ability to clot and then the injury cannot stop bleeding.
Low platelet counts are treated with platelet transfusions in severe cases, but usually it can be managed by taking simple precautions. If bleeding occurs, apply immediate, firm pressure to the area until bleeding has stopped. For a nosebleed, apply pressure just below the bridge of the nose and keep the head raised until the bleeding stops. If there is a major injury or bleeding starts at random, go to the nearest hospital or emergency room immediately.