A swollen and tender ankle that is still movable is likely a sprained ankle, while a broken ankle is typically swollen, bruised, numb, tender and deformed, according to Sports Injury Advice. Sprains usually result from stepping on an uneven surface, twisting the foot or losing balance. A broken ankle usually results from a hard fall or heavy impact.
Common symptoms of a sprain include pain, swelling and inflammation, according to the National Health Service of the United Kingdom. This type of injury occurs when one or more ligaments are twisted, torn or stretched.
Sports Injury Advice explains that a sprained ankle is usually more painful than a broken one. However, a person can still walk with a sprained ankle, but the injury is often painful. When a person experiences sudden, severe pain and the ankle becomes deformed, the injury is likely a broken ankle, according to Sports Injury Advice, and individuals often cannot place any weight on the affected foot. The NHS states that pain, inability to walk, swelling and a "crack" sound usually indicate a broken or fractured ankle.
It is important to see a health care provider to determine whether an ankle is broken or simply sprained, according to Sports Injury Advice. Doctors generally take an X-ray to find out the exact injury and conduct a stress test to determine if surgery is necessary.