A sprain is an injury that happens when you stretch or tear the tough, rope-like tissues (called ligaments) that connect your bones at a joint. The most common place to get a sprain is your ankle: if you're running and suddenly twist your foot the wrong way, you might sprain your ankle. Basketball players often sprain their ankles when they land awkwardly after jumping for a rebound.

When you sprain something, the area usually swells up, hurts quite a bit, and might bruise. A sprained ankle might make it painful to walk for several days or even weeks. Doctors often recommend rest, ice, compression with a bandage, and keeping the injured area elevated (that's called the RICE method: Rest, Ice, Compression, Elevation).

People sometimes confuse sprains with strains, but they're different. A strain injures a muscle or tendon (the tissue connecting muscle to bone), while a sprain injures a ligament (the tissue connecting bone to bone). You might strain your hamstring muscle by running too hard, but you might sprain your wrist when you fall and land on your hand the wrong way. Both hurt, but they're injuries to different parts of your body.