The presence of leg pain in fever is mostly considered to be caused by excessive lactic acid accumulation in the muscles. Thermogenic sources can lead to an increase in the production of inflammatory factors in the body due to the stimulation of nerves by viruses and bacteria. The nutrient metabolism of the cells in the muscles is blocked to a certain extent, and the cells do not receive sufficient oxygen supply. The thermogenic source acts on the thermoregulatory center, and motor nerve impulses occur, causing the skeletal muscles of the whole body to spasm. At this time, you can take some antipyretic and analgesic drugs to relieve, such as ibuprofen or acetaminophen, and patients need to take sufficient rest, and avoid strenuous activities, strenuous activities may aggravate the accumulation of lactic acid, resulting in the aggravation of leg pain.