There may be a relationship between arterial ductus arteriosus and low-grade fever. Arterial ductus arteriosus is a common congenital heart condition in which the arterial duct connects the aorta to the pulmonary artery, usually to the left pulmonary artery. The ductus arteriosus is an essential structure during fetal life, and the fetus is supplied with blood from the pulmonary artery to the arteries of the lower extremities. The ductus arteriosus usually heals and repairs itself after birth; failure to do so is called arterial ductus arteriosus. When low-grade fever occurs, it is mainly due to bacterial infections, viral infections, mycoplasma infections, and mycobacterial-type infections. If there is some relationship between low-grade fever and the ductus arteriosus, it is mainly due to the fact that the shunt between the left and right sides of the lungs causes sludge in the lungs, which becomes a perfect place for bacterial cultures, thus making the lungs more susceptible to infections. Arterial ducts can close on their own within a few months after birth. With age, if the arterial ducts are not closed, parents are advised to take their children to the hospital for timely hospitalization and surgical treatment, which, if not treated in time, may lead to complications that can affect the patient’s quality of life, or even put his or her life at risk.