Seat belts can help save lives in a car accident. But if your body was thrown forward against the seat belt, you may have a bruise (contusion) or scrape (abrasion) on your neck, chest, back, or belly (abdomen).
A bruise may cause changes in skin color. For instance, the skin may turn blue or black. Swelling and pain may also occur. A scrape may cause pain, redness, swelling, and bleeding.
Most bruises and scrapes are not serious. They generally take a few days or longer to heal.