Whether platelet 40×10^9/L can be recovered mainly depends on the cause of the disease. If it is caused by viral infectious factors or rheumatoid immune system diseases, it can be recovered gradually after treatment, but if it is caused by primary thrombocytopenic purpura or myelopoietic dysfunction, it is difficult to recover. 1. Infectious factors: If the platelet reduction is caused by viral infectious factors, regular anti-infectious treatment is needed, and the platelet will gradually return to normal. 2. Rheumatic immune system diseases: such as systemic lupus erythematosus, rheumatoid arthritis, dry syndrome, etc., platelets can be gradually recovered through active treatment of the primary disease and standardized treatment. 3. Primary thrombocytopenic purpura: mainly characterized by thrombocytopenia, there will be severe bleeding, such as nosebleeds, gum bleeding, gastrointestinal bleeding. If such cases are not actively treated, it is usually difficult to return to normal. 4. Bone marrow hematopoietic dysfunction: if the bone marrow hematopoietic stem cells are damaged, aplastic anemia and myelodysplastic syndromes will occur, and the platelet count of such patients will decrease, and it is difficult to return to normal if not actively treated. Reduced platelet count may also be caused by other reasons, it is recommended to pay attention to find the cause of the disease in a timely manner to the hospital, for the cause of the treatment, to avoid delaying the condition.