Low fever is harmful to all aspects of a person, mainly affecting the immune system, nervous system and respiratory system of a person. Body temperature is one of the four vital signs of a person. A prolonged low fever indicates that a person’s body is unhealthy and there is disease, which seriously affects the normal immunity and makes the body susceptible to illness. It also has an effect on the blood system, with an increase or decrease in the number of white blood cells and a disruption of the body’s fluid regulation. Patients may have headache, dizziness, weakness, fatigue, drowsiness, cough, coughing, five heart flushes, backache, leg pain and generalized aches and pains, which can seriously affect the quality of life. Prolonged low fever is a clinical symptom that requires active identification of the pathogen to treat the phenomenon of prolonged low fever. From traditional Chinese medicine, prolonged low fever belongs to yin deficiency, which can lead to imbalance of yin and yang in the body and cause functional diseases.