There are various causes of thrombocytopenia and leukocytopenia, the common causes are: a. Acute infection or medication, causing low platelets and leukocytes, common cold patients, while having fever, taking antiviral drugs and anti-inflammatory and pain-relieving drugs, the patient may have thrombocytopenia and leukocytopenia. Because viral infections and anti-inflammatory and pain-relieving drugs may cause a decrease in white blood cells and platelets. When the cold is controlled, the number of white blood cells and platelets will gradually return to normal. Second, aplastic anemia, which is a bone marrow hematopoietic failure disease. Due to the damage of hematopoietic stem cells, the ability to produce leukocytes and platelets is reduced, resulting in a decrease in the number of leukocytes and platelets. Third, it is seen in patients with malignant tumors after chemotherapy, which can also cause a decrease in the number of white blood cells and platelets due to the toxic side effects of chemotherapy drugs.