Low platelets usually need to be rechecked in about 15 days. However, if the platelets are significantly low, the blood count should be rechecked once a day. For chemotherapy-induced thrombocytopenia, even a daily review is needed. 1. The normal value of platelets is (100~300) x 10^9/L. If the platelets are lower than the normal value, they are on the low side and usually need to be rechecked once every 15 days. The main purpose of the review is to find the cause of low platelets, such as acute infection, immune system abnormality, hypersplenism and so on. 2. If the platelets are obviously low and serious, the blood routine should be rechecked once a day. 3. For thrombocytopenia caused by chemotherapy, platelets should be transfused under the guidance of professional doctors, and even need to be rechecked once a day. Therefore, once the situation of low platelets occurs, it is recommended to cooperate with professional doctors to improve the relevant examination as soon as possible to find the cause and receive standardized treatment.