Fatigue generally does not cause fever, but excessive fatigue may cause sleep disorders, including difficulty in falling asleep, waking up easily and dreaming more, thus affecting the patient’s sleep time and quality of sleep. Prolonged sleep deprivation may cause a decline in the immune function of the body, which may induce infections, such as bacterial infections and viral infections, and the patient may develop fever when there are the above mentioned infections. In addition, excessive fatigue may also reduce the immune function of the human body, which may also induce some infectious diseases, and when the infection occurs, the patient may also have a fever. Common causes of fever are respiratory tract infections, urinary tract infections and tonsillitis, etc. Most of them are considered to be caused by bacterial infections, and patients with viral infections can also have fever, and common clinical diseases include encephalitis and upper respiratory tract infections.