A hamstring strain is an injury that occurs when the muscles at the back of the thigh are stretched too far or torn. This can happen during activities that involve running, jumping, or sudden stops. Symptoms often include pain, swelling, and difficulty moving the leg. Treatment for a hamstring strain typically involves rest, ice, compression, and elevation, often referred to as the RICE method. In more severe cases, physical therapy may be needed to help restore strength and flexibility. Most people recover fully with proper care and rehabilitation.