A high fever that does not go away is not necessarily due to leukemia, other diseases may also have a high fever that does not go away, and the cause needs to be clarified and treated symptomatically. A high fever that does not subside means that the body temperature exceeds 38°C and does not resolve for a longer period of time. The phenomenon may be caused by a variety of reasons. Fever is one of the most common symptoms of leukemia. The main cause of high fever in leukemia patients is infection, which can be accompanied by sepsis and septicemia in severe cases, and anti-infection treatment needs to be actively given. In addition to leukemia, typhoid fever, bacterial dysentery, hepatitis A, influenza, epidemic B encephalitis, and many other diseases may also cause symptoms of high fever that does not go away. Fever caused by inflammation needs to be treated with antibiotics, and those caused by viral infections need to be treated with antiviral drugs together with antipyretics, such as acetaminophen and ibuprofen. If leukemia is suspected, you need to visit the hematology department of the hospital to do blood routine, bone marrow biopsy and blood biochemistry tests to clarify the diagnosis and actively treat the disease.