What should you know about foot and knee swelling?

Knee swelling can be fluid inside the joint or inflammation in tissues around it. A twist during sport may present with swelling and instability in an ACL tear or meniscus tear. A soft fullness behind the knee can occur with a Baker's cyst. Painful warmth around the kneecap may occur with knee bursitis. Gout can present with sudden, intense joint pain, redness, and warmth. Gradual swelling and stiffness with activity can accompany knee osteoarthritis. Foot swelling may be a separate strain or may reflect how you are walking to protect the knee. These patterns guide assessment but do not establish a diagnosis by themselves.

Pause running, jumping, and deep squats while the knee is swollen. Rest with the leg supported, use a cloth-wrapped cool pack for short periods, and choose shoes that do not compress the foot. Gentle range-of-motion exercises can help if they remain comfortable. Do not force a locked or sharply painful knee. A clinician may examine the joint and, when fluid is restricting movement or its cause needs checking, discuss joint aspiration. Arrange review when swelling lasts, recurs, or changes your walking pattern.

Seek urgent care for a hot, very painful swollen knee with fever or feeling unwell, sudden calf or leg swelling with breathing difficulty or chest pain, or a cold, pale, blue, or numb foot. Get prompt assessment after a major injury, visible deformity, inability to bear weight, or a knee that cannot straighten. Spreading redness also needs timely review.

Ask whether the swelling is inside the joint or around it, whether an injury or inflammatory condition fits the pattern, and whether imaging or fluid testing is needed. Mention fever, recent exercise, previous attacks, medicines, and exactly when foot swelling appeared.