Fever of malignant tumor usually refers to fever, the pattern of which may be characterized by low-grade fever, long duration and easy to be repeated. 1. Low fever: after the formation of malignant tumor in the body, due to the secretion of tumor tissues will produce and release endogenous pyrogen, such as tumor necrosis factor, interleukin, etc., some toxins of these pyrogens may cause the body to have a low fever, which is usually not more than 38.5 degrees, and the patient will have fatigue, loss of appetite and other uncomfortable symptoms. 2. Long duration: malignant tumors cause fever, may last longer, and take antipyretic drugs or antibiotics have no obvious effect. The reason may be that the lack of granulocytes lasts for a long time, or the rapid growth of tumor cells leads to tissue ischemia and necrosis. 3. Easily repeated fever: in the early stage of malignant tumor formation, the patient may gradually get better after the fever symptoms appear, but the fever symptoms will often appear again. The reason may be due to the tumor patients due to their own immunity, coupled with the chemotherapy period of immunity decline, there may be repeated bacterial or viral invasion caused by infectious fever. Fever caused by malignant tumors will have typical symptoms and manifestations, which are obviously different from infectious fever. Once these situations occur, it is necessary to seek medical treatment in time to carry out corresponding examination, and after clear diagnosis, it is necessary to treat as soon as possible to prevent serious consequences.