Knee still swollen after 2 weeks: what to know

Swelling can reflect fluid inside the joint or inflammation in nearby tissues. A recent twist may involve an ACL or meniscus injury; gradual swelling can occur with knee osteoarthritis. A Baker's cyst may create fullness behind the knee, while bursitis affects a small cushioning sac. Sudden heat, redness and marked tenderness can occur with gout or an infection and need prompt clinical review. Knee swelling is a symptom, not a diagnosis, so the pattern, examination and sometimes imaging help distinguish causes.

Reduce activities that increase swelling, but keep the knee gently moving within comfort so it does not become stiff. Rest with the leg supported, use a wrapped cold pack for short periods, and avoid placing ice directly on skin. A clinician may check stability, range of motion and fluid; joint aspiration can sometimes both test the fluid and ease pressure. Do not begin intensive exercise or self-treat with medication without checking that it is suitable for you.

Arrange a medical assessment soon for swelling that persists, repeatedly returns, or causes locking, catching or difficulty bearing weight. Seek urgent care if the knee becomes hot and red with fever, pain becomes severe, the leg changes colour, or you cannot move or bear weight after an injury.

Ask what findings suggest fluid inside the joint, whether imaging or aspiration is appropriate, and which movements are safe while swelling settles. Mention when the swelling began, any twist or impact, morning stiffness, fever, redness and episodes of locking.