Possible reasons for normal blood count but low fever include: physiological reasons, autonomic dysfunction, hyperthyroidism, malignant tumors and so on. Physiological reasons: Normal people can have low fever under certain circumstances, such as mental stress, pregnancy, pre-menstrual period of women, etc., but there is usually no abnormal change in blood count. 2. Autonomic dysfunction: autonomic dysfunction can affect the thermoregulation process, resulting in more heat production than heat dissipation and cause fever, mostly low fever, which is functional fever, and thus there is no abnormal change in blood routine. 3. Hyperthyroidism: Hyperthyroidism patients due to the body’s metabolic exuberance can appear low fever performance, some patients may not appear abnormal blood routine. 4. Malignant tumors: many malignant tumors do not have abnormal blood counts in the early stage, but the absorption of tumor necrotic substances and the release of certain thermogenic factors can also cause patients to have low fever. The above are only some of the common causes. Patients with low fever but normal blood counts are recommended to go to the hospital as soon as possible, so that the professional doctors can evaluate the condition carefully and clarify the cause of the disease as soon as possible and then treat the patient in time.