What causes knee pain?

Pain after a twist, landing, or collision can involve the ACL or another internal structure. Pain around the front of the knee may relate to chondromalacia patellae, while soreness on the outer side can occur with IT band syndrome. A tender fluid-filled swelling may be a Baker's cyst or knee bursitis. Knee osteoarthritis can cause activity-related pain and stiffness. Gout can produce a sudden hot, swollen, intensely painful joint. The location, timing, swelling, and movement pattern help separate these possibilities.

For a recent flare, reduce the activity that provokes pain and keep gentle movement within a comfortable range. Supportive footwear, paced tasks, and a cold pack wrapped in cloth may help soreness. Do not rely on a label from symptoms alone: an examination can check stability, swelling, kneecap movement, muscle control, and nearby areas. Treatment depends on the cause rather than pain intensity by itself.

Arrange assessment when pain persists, recurs, limits walking, or follows a significant injury. Seek urgent care for a deformed knee, inability to bear weight, sudden major swelling, a hot swollen joint with fever, or severe pain after an injury. Calf swelling or breathlessness alongside leg symptoms also needs urgent medical attention.

Which structures could be causing pain in this location? Do I need tests or imaging? What movements should I modify now? Which changes would mean I should return sooner?