Unilateral ankle edema needs to be alert to ankle sprain, gout, lower extremity vascular lesions, etc.. 1. Ankle sprain: if you perform strenuous exercise or maintain an improper posture, it is easy to induce muscle or ligament strains in the ankle joint, and then localized edema occurs. 2. Gout: If there is a history of gout, the purine content is too high, it is easy to trigger gout attacks, and then appear unilateral redness, swelling and pain in the ankle joint. 3. Lower extremity vascular lesions: If there are lower extremity vascular lesions, such as lower extremity varicose veins, lower extremity arterial embolism, etc., it is easy to cause edema in the ankle joint. Caused by unilateral ankle edema causes more, may also be related to cellulitis, rheumatoid arthritis and other diseases, if the symptoms continue to have no relief, it is recommended to go to the hospital in a timely manner to find out the cause of the disease, by the doctor targeted treatment.