What should you know about knee swelled up?

Swelling may sit inside the joint as an effusion or in nearby soft tissue. It can follow a twist, impact, repeated loading, or an inflammatory flare. ACL tears and meniscus tears can present with swelling after injury; gout, knee bursitis, osteoarthritis, and a Baker's cyst can also affect the area.

A clinician will ask when it began, whether the knee locked or gave way, and whether you can bear weight. Examination may include checking the skin, joint motion, stability, and calf. The swelling alone cannot identify its cause.

Reduce activities that increase pain or pressure, and keep gentle movement within the range advised by a clinician. Elevate the leg when resting. A wrapped cold pack may help short-term if you can safely feel the skin; stop if numbness or skin irritation develops.

Do not massage a hot, acutely swollen knee or use leftover antibiotics. Arrange an assessment if swelling persists, recurs, limits walking, or follows a significant injury. Joint aspiration is a clinician-led option in selected cases, both to test fluid and sometimes ease pressure.

Get urgent medical care for a hot red knee with fever, rapidly increasing swelling, severe pain, inability to bear weight, or a knee that is stuck. Emergency symptoms include new chest pain or breathlessness, or a leg and foot that become cold, pale, numb, or weak.

Ask what the examination suggests, whether imaging or fluid testing is needed, which activities are safe today, and how to recognise infection, a circulation problem, or a clot-related emergency.