Chills and body aches are often caused by viral and bacterial infections, and common diseases include upper respiratory tract infection and acute pyelonephritis. 1. Upper respiratory tract infection: often caused by bacteria, viruses and other pathogenic microorganisms, in the early stage of fever, due to the upward shift of the thermoregulation point, so that the skin capillary contraction, skin temperature is reduced, and chills, weakness of the limbs, muscle aches and pains and other symptoms, caused by viruses can be through the antiviral particles such as anti-viral, bacterial caused by amoxicillin, zoflurixacin, roxithromycin, and other anti-infective. 2. Acute pyelonephritis: the pathogenic microorganisms invade the renal pelvis and renal parenchyma, the onset of the disease is relatively acute, there may be high fever, fatigue, chills, generalized aches and pains, and other systemic symptoms, but also manifested as lumbar pain, frequency of urination, urinary urgency, pain in the urine, etc., through the levofloxacin and other anti-infective treatment. There are also many infectious diseases, chills and body aches before fever, when there are persistent body aches and chills, it is recommended to consult a doctor as soon as possible, to be clear after the cause of targeted treatment.