When should you see a doctor about knee pain?

Knee pain can arise from tissues around the joint, including tendons, ligaments, cartilage, or a fluid-filled sac. An ACL tear may follow a sudden twist and may be accompanied by instability. A Baker's Cyst can cause fullness behind the knee. Pain that builds with activity may reflect joint irritation or wear, but the location and movement pattern still need assessment.

Note where the pain sits, when it began, and whether stairs, squatting, rest, or a particular injury changes it. Pain alone cannot identify its cause, so an examination is more useful than guessing from one symptom.

Reduce activities that clearly worsen the pain, but keep gentle movement within comfort so the knee does not become stiff. Use a cold pack after activity if swelling is present, and choose stable footwear. Do not return to sport through sharp pain or a feeling that the joint is unreliable. Depending on the cause, care may include physiotherapy, a brace, or another treatment discussed after assessment.

Get urgent help if pain follows a major injury, the knee looks deformed, you cannot bear weight, or it becomes suddenly very swollen. A hot, red knee with fever needs urgent medical attention. Arrange routine review for pain that persists, worsens, repeatedly interrupts sleep, or prevents work and everyday tasks.

Ask what the examination suggests, whether imaging is useful, and which activities are safe. Ask how to pace exercise, what improvement should look like, and whether options such as injections, bracing, rehabilitation, or joint replacement are relevant to your situation.