An ankle sprain occurs when one or more ankle ligament gets overly stretched. Ligaments are strong bands of tissue that bind and support the bones and other structures that make up the ankle. In more severe ankle sprains, the ligament(s) tear—either partially or completely—and there may be an audible popping noise at the moment of injury.

Ankle sprains are quite common and can occur when the ankle rolls outwardly (eversion) or inwardly (inversion), causing the ligament(s) to stretch beyond normal limits, or even tear. Falls, twists, or blows to the ankle during sports or other activities can cause this injury, as well as wearing improper footwear, running on uneven surfaces, or having weak ankles.

Depending on the injury’s severity, an ankle sprain will be classified as Grade I, Grade II, or Grade III. Grade I sprains involve ligament(s) being overly stretched but not torn, with symptoms of mild pain, swelling, and ankle instability. There may also be some difficulty bearing weight. A Grade II sprain usually involves a partial tear of the ligament which brings more intensity in these symptoms, along with possible bruising. With a Grade III sprain, the ligament is completely torn, the symptoms are severe, and it may not be possible to put weight on the affected foot at all. 

To diagnose and grade an ankle sprain, a podiatrist will perform a physical examination, checking for tenderness and range of motion in the ankle. For more severe sprains, X-rays or other imaging studies may be necessary. 

It is vitally important to have an ankle sprain treated properly as improper healing often leads to future ankle sprains and possibly even chronic ankle stability. Treatment for an ankle sprain will vary, depending on its severity, and may include the RICE method (Rest/Ice/Compression/Elevation), physical therapy, bracing, medications, and possibly even surgery to repair a torn ligament. Rehabilitation is very important for the sprain to heal properly and to restore functionality.