An ankle sprain is an injury to one or more ligaments in the ankle, usually on the outside of the ankle. Ligaments are bands of tissue—like rubber bands—that connect one bone to another and bind the joints together. In the ankle joint, ligaments provide stability by limiting side-to- side movement.

Some ankle sprains are much worse than others. The severity of an ankle sprain depends on whether the ligament is stretched, partially torn, or completely torn, as well as on the number of ligaments involved. Ankle sprains are not the same as strains, which affect muscles rather than ligaments. Sprained ankles often result from a fall, a sudden twist, or a blow that forces the ankle joint out of its normal position. Ankle sprains commonly occur while participating in sports, wearing inappropriate shoes, or walking or running on an uneven surface. Sometimes ankle sprains occur because of weak ankles, a condition that some people are born with. Previous ankle or foot injuries can also weaken the ankle and lead to sprains.

The signs and symptoms of ankle sprains may include:
 Pain or soreness
 Swelling
 Bruising
 Difficulty walking
 Stiffness in the joint

These symptoms may vary in intensity, depending on the severity of the sprain. Sometimes pain and swelling are absent in people with previous ankle sprains—instead, they may simply feel the ankle is wobbly and unsteady when they walk. Even if you don’t have pain or swelling with a sprained ankle, treatment is crucial. Any ankle sprain—whether it’s your first or your fifth—requires prompt medical attention.