Usually, the fever of bacterial infection can be reduced in a few days depending on the site of infection, the patient’s physical condition, the type of bacteria, etc., and cannot be generalized. Depending on the site of infection, fever can be reduced in 3-5 days for upper respiratory tract infections; 1-3 days for gastrointestinal tract infections; and about 7 days for acute pyelonephritis, purulent cholangitis, bacterial endocarditis, etc. after regular treatment. Depending on the physical condition of the patient, if the patient is a previously healthy adult and an elderly person, the fever will subside faster, and if there are patients with chronic underlying diseases with immune dysfunction, such as organ transplants, tumors, etc., the fever of the infection that occurs can be longer. Depending on the type of bacteria, more virulent bacteria such as Streptococcus pyogenes and Staphylococcus aureus can cause very serious infections that can lead to systemic toxic shock syndrome and even life-threatening, and the fever can last longer. In case of fever with bacterial infection, drink more water, eat more fresh vegetables and fruits, and go to the hospital fever clinic promptly.