A hematoma is a localized collection of blood outside of blood vessels, usually caused by an injury or trauma. When blood vessels are damaged, blood leaks into surrounding tissues, leading to swelling and discoloration. Hematomas can occur in various parts of the body, including the skin, muscles, and organs. The severity of a hematoma can vary, with some being minor and resolving on their own, while others may require medical intervention. Treatment options may include rest, ice, compression, and elevation (often referred to as the RICE method), or in more serious cases, drainage or surgery may be necessary.