Ouch! Many of us have experienced that moment when we realize that we’ve done something to cause an injury that we can’t just walk off. We may “see stars” or experience such a sharp pain that we know that we’ve done damage. Ankle sprains, one of the most prevalent injuries of the musculoskeletal system, are so common that it’s estimated that one ankle sprain occurs per 10,000 people each day. Back strains are also quite common: according to Cleveland Clinic, next to headaches, back problems are the most common complaint to medical professionals.

Sprains and strains are very common injuries, and while they’re often mentioned together, they’re quite different.

Sprain vs. Strain: What’s the Difference?

Sprains and strains have similar symptoms, but they occur in different body parts. A sprain is the stretching or tearing of ligaments, which connect bones. For example, an ankle sprain is an injury to ligaments in the ankle joint.

A strain, on the other hand, is an injury that involves stretching or tearing a muscle or tendon, which connect muscles to bones. Strains are not uncommon in the lower back or the hamstring.

What Are the Signs?

Swelling and bruising are both common symptoms of a sprain or strain. Swelling typically occurs shortly after the injury, while bruising may not appear until hours later or may not show at all. Bruising also may occur some distance from the affected joint, as blood from damaged tissue seeps along muscles and around the joint before coming close to the skin.