I think I pulled my hamstring: what should I know?

The hamstrings are muscles at the back of the thigh that help bend the knee and extend the hip. A strain may happen during acceleration, a jump, a sudden stretch, or an awkward step. Symptoms can include sharp pain, tightness, tenderness, swelling, bruising, or weakness. [Thigh Pain](/symptoms/thigh-pain/) has several possible causes, so the location, movement, and onset help a clinician judge the injury.

Stop the activity that caused pain and avoid sprinting, deep stretching, and forceful massage at first. Rest from aggravating loads, use a wrapped cold pack for short periods, and raise the leg when comfortable. Walk only as far as you can without a marked limp. As pain and strength improve, supervised [Exercise Therapy](/treatments/physiotherapy-and-rehabilitation/exercise-therapy/) can rebuild control. A gradual [Return-to-Sport Programme](/treatments/physiotherapy-and-rehabilitation/return-to-sport-programme/) reduces the chance of rushing back.

Arrange prompt care for a sudden pop, major bruising, a visible dip in the muscle, inability to walk normally, or substantial weakness. Seek urgent help for a cold, pale, numb, or rapidly swelling leg. Assessment is also wise when pain returns with light activity or progress stalls. [Sports Physiotherapy](/treatments/physiotherapy-and-rehabilitation/sports-physiotherapy/) can help distinguish a strain from other causes and plan progression. A clinician may discuss [PRP Injection](/treatments/non-surgical-orthopedics/prp-injection/) only when appropriate; it is not a first step for every injury.

How severe does this strain appear? When may I walk, jog, stretch, and strengthen? What signs show that the muscle is ready for sport? Do I need imaging or a rehabilitation programme?