A bruise occurs when a force causes blood vessels to break. Blood leaks into areas under the skin, resulting in pain, swelling, and skin discoloration.
Review Date 5/3/2021
Updated by: Linda J. Vorvick, MD, Clinical Associate Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.