The causes of low-grade fever and sweating in children are considered as follows:1. The most common cause of fever and sweating is due to infection, most likely viral or bacterial infections, not excluding infections such as Mycoplasma pneumoniae, which should be examined in the hospital blood system, to clarify the etiology of the disease, and according to the type of infection, choose the appropriate medication, and the infection control, then the fever can subside to normal.2. Blood system disorders, such as leukemia, can be Repeated low fever, sweating, often accompanied by anemia, bone and joint pain, should go to the hospital for routine blood tests, a clear diagnosis. 3, tuberculosis, if the child’s low fever for the afternoon low fever, accompanied by night sweats, lethargy, loss of appetite, coughing, should go to the hospital for chest radiographs and tuberculin experiments in order to clarify the diagnosis, give treatment. In short, the baby’s long-term low-grade fever, sweating should be taken seriously, to the hospital to avoid delays.