Frequent low fever may be caused by autonomic dysfunction and tumor. 1. Autonomic nerve function disorder: such as female menopausal syndrome, hyperthyroidism, etc., may cause patients to have autonomic nerve function disorder, endocrine imbalance, triggering low-grade fever, which will lead to the phenomenon of frequent low-grade fever. 2. Tumor: due to the usual bad lifestyle, such as smoking, drinking, obesity, bad dietary habits, etc., it is easy to induce tumors, resulting in the proliferation of local tissue cells, due to the rapid growth of tumors, tumor cells will release a large number of thermogenic sources, which further act on the thermoregulatory center, resulting in the phenomenon of frequent low-grade fever. If you have low fever frequently, it is recommended to go to the hospital as soon as possible, through the corresponding examination, according to the specific situation, under the guidance of the doctor, to carry out symptomatic treatment.