Warmth and pain in the right leg are usually caused by pathological factors, such as lumbar disc herniation, aseptic inflammation of muscles and fascia, allergies and other symptoms of the disease. 1. Herniated lumbar intervertebral disc: If the herniated nucleus pulposus compresses the nerve roots of the lower limbs and the nerves in the legs are stimulated, it may cause sensory abnormalities in the lower limbs, manifesting as warmth and pain in the legs. 2. Aseptic inflammation: if you exercise excessively or do heavy physical labor frequently, it is more likely to have muscle strain, triggering aseptic inflammation of muscles and fascia. It will show the swelling of local tissues and the feeling of heat or pain, and the right leg fever and pain. 3. Allergy: If the skin of the right leg comes into contact with certain allergic substances, the body’s immune response is too strong, which may lead to dilation of capillaries in the leg, showing localized skin redness, swelling, heat and pain. In addition to the above reasons, trauma, purulent infections and varicose veins may also cause fever and pain in the legs. If the situation occurs and cannot be relieved by itself, it is recommended to consult a doctor in time, and under the guidance of the doctor, improve the relevant examination to clarify the cause of the disease.