Bacterial fever is usually more severe during the course of the disease for 2-5 days, but the exact duration is related to the severity of the patient’s illness, treatment, and individual circumstances and cannot be generalized. The most common symptom of bacterial infection is fever, which is usually more severe in patients 2-5 days into the course of the disease, and this period is also a critical time for the disease to get better and get worse. At this time, patients will have high fever, cough, coughing, poor breathing, fatigue, loss of appetite and other symptoms, if the type of bacterial infection is clear, antibiotics sensitive to the causative bacteria can be used to treat the patient’s symptoms will gradually improve after symptomatic treatment. If the type of fine infection cannot be determined temporarily, the patient can be treated with broad-spectrum antibiotics. In addition, if the patient has a bacterial infection combined with pneumonia or sepsis, the degree of disease may be more severe and more aggressive treatment is required. Therefore, it is recommended that patients with bacterial fever should go to the hospital as soon as possible, pay attention to rest, eat a light diet, and eat more protein-rich foods.