Localized redness, swelling and pain in the calf is considered to be related to gout, osteomyelitis, cellulitis, etc. 1. Gout: due to eating more purine food leads to sudden pain in the calf, localized redness and swelling, through the uric acid test can be a clear diagnosis, oral uric acid lowering drugs such as allopurinol can reduce the symptoms. 2. Osteomyelitis: Osteomyelitis can be characterized by localized redness, swelling and pain in the bones, generalized fever, chills, fatigue and weakness, etc., and can be clearly diagnosed by radiographs. 3. Cellulitis: most common in hemolytic streptococcal infections, can appear in the soft tissue of the skin, redness, swelling and pain, elevated skin temperature, elevated blood leukocytes, and severe may also be pus. There are many causes of localized redness, swelling and pain in the calf, it is recommended to go to the hospital in time for examination, to clarify the specific causes for further treatment.