Thrombocytopenia means you don't have enough blood platelets, cells in your blood that stick together to help it clot.
Thrombocytopenia often occurs as a result of a separate disorder, such as leukemia or an immune system problem. Or it can be a side effect of taking certain medications. It affects both children and adults.
It might not cause you any health problems at all. However, in rare cases, the number of platelets may be so low that dangerous internal bleeding occurs. If you do have symptoms like bleeding too much, treatments can help.