Possible causes of sudden pain in the foot like a sprain include arthritis, synovitis, vasculitis, gout, etc. Further examination is needed to determine the cause. 1. Arthritis:Generally caused by degeneration, infection, trauma or other factors of the human body joints and their surrounding tissues inflammatory diseases, joints may appear sudden pain, swelling and other symptoms, long-term development may appear limited activities. 2. Synovitis: generally caused by trauma, excessive exercise, infection and other factors lead to inflammation in the synovial membrane, synovial membrane hyperplasia, increased secretion of fluid, stimulation of the surrounding joints, sudden pain, joints may be swollen, limited mobility and other symptoms. 3. Vasculitis: Vasculitis is a blood disease, usually caused by inflammation within the blood vessels leading to occlusion, narrowing of the blood vessels, blood circulation is impaired, which leads to ischemia of all blood-supplied limbs, and thus pain symptoms can occur. 4. Gout: usually due to improper diet, resulting in hyperuricemia, uric acid crystals in the blood are deposited in the joints, resulting in redness, swelling, heat and pain in the joints. The foot suddenly like a sprain like pain symptoms, it is recommended to go to the regular hospital in a timely manner, identify the cause, and active treatment.