Platelets only 3×10^9/L is more serious, this condition indicates that the platelets have been too low, it is more dangerous. The normal range of platelets is (100~300)×10^9/L, the value of platelets is lower than 100×10^9/L for thrombocytopenia, if the platelets are only 3×10^9/L, it is considered to be severe thrombocytopenia, which can be seen in primary immune thrombocytopenia, aplastic anemia, acute leukemia, pharmacological factors and so on. The main danger of low platelets is that they can cause a range of bleeding symptoms, including gastrointestinal bleeding, pulmonary hemorrhage, or cerebral hemorrhage, and severe bleeding can be life-threatening. If the platelet is only 3×10^9/L, it is recommended to go to the regular hospital to do the relevant examination in a timely manner, to clarify the cause of the disease, and to receive targeted treatment under the guidance of the physician, such as platelet transfusion or treatment of the primary pathology, such as patients with cataracts oral cyclosporine.