When the platelet is 30×10^9/L, it belongs to the platelet is seriously low, whether it is a serious disease, need to be combined with the etiology of thrombocytopenia to see, diagnosis of aplastic anemia, leukemia, the condition is more serious; hyper-splenism and so on, the prognosis is better. When the platelet count is <100×10^9/L, it is called thrombocytopenia, which can be seen in aplastic anemia, leukemia, hypersplenism, autoimmune diseases, drug effects and so on. All of these conditions can lead to a reduced platelet count. Aplastic anemia, leukemia, etc., is the bone marrow hematopoietic function is impaired, resulting in a reduction in platelet production, this type of disease when the platelet is 30 × 10^9 / L, represents the condition is already very serious, the risk of bleeding is high, and the disease itself is poor prognosis, is a serious disease. Thrombocytopenia caused by excessive destruction of platelets due to hypersplenism, etc. is relatively milder and has a relatively better prognosis. Thrombocytopenia caused by drug action, after stopping the drug, platelets can slowly rise, not a major disease. However, all of them have some risk of bleeding. When the platelet is low, avoid strenuous activities or bumping, it is recommended to consult a doctor in time, after a clear diagnosis, standardized treatment.