Foot sprain three months or swelling may be ligament injury or tear, insufficient rest, vascular disease of the lower extremities, inflammation and infection, etc., through physical therapy or surgical treatment, adequate rest, medication to improve the symptoms. 1. Ligament injury or tear: foot sprain triggered acute ligament injury or ligament tear, the recovery time is relatively slow, may be three months is still swollen, early ice packs, hot compresses to ease the swelling in the late stages, you can choose to support, plaster fixation to alleviate the symptoms of the ligament tear is more serious to carry out ligament repair surgical treatment. 2. inadequate rest: foot sprain without adequate rest, often walking on the ground swelling is difficult to subside, these patients should pay more attention to rest, no healing can not often walk on the ground, under the guidance of the doctor to use plasters, such as Yunnan Baiyao cream, so as to reduce the swelling. 3. Lower extremity vascular disease: foot sprained within three months of the lower extremity vascular disease, such as lower extremity venous thrombosis, can cause sprained parts of the blood return obstruction, a large amount of blood stagnation in the ankle and swelling, with low molecular weight heparin to prevent the formation of blood clots, but also through the placement of thrombosis or decompression of the surgical treatment, will alleviate the symptoms of swelling. Foot sprain three months or swelling is more serious, it is recommended to consult a doctor in time, follow the doctor’s instructions for treatment, do not blindly use drugs.