An ankle sprain is an injury that causes a stretch or tear of one or more ligaments in the ankle joint.
Ligaments are strong bands of tissue that connect bones at the joint.
Sometimes sprains are just classified as mild or severe, depending on the amount of ligament damage. Most sprains occur on the outside part of the ankle, but they can occur on the inside as well. A sprain is caused by twisting your ankle. Your foot usually turns in or under but may turn to the outside. To diagnose a sprained ankle, the doctor will review how the injury occurred and consider your symptoms.