What causes hot, red, swollen joint?

Gout and pseudogout are crystal-related attacks that can begin suddenly, often affecting one joint with intense tenderness and swelling. Rheumatoid arthritis can cause inflammatory swelling and stiffness, sometimes affecting several joints. Septic arthritis is an infection inside a joint and can damage the joint quickly without treatment. A skin wound, recent procedure, injection, or illness may be relevant. The appearance alone cannot distinguish these causes; examination and sometimes joint-fluid testing are used.

Rest the joint in a comfortable position and avoid strenuous use. Keep the area clean if there is a nearby wound, and note when the heat, redness, and swelling began. Do not squeeze the joint or start leftover antibiotics. A clinician may need to assess your temperature, movement, skin, and medical history before choosing treatment. Seek advice promptly even if the pain eases temporarily.

A hot, red, swollen joint with fever, chills, feeling faint, severe pain, or inability to move needs urgent medical assessment. Treat sudden worsening as urgent, particularly after surgery, an injection, or a break in the skin. People with reduced immune defences or a prosthetic joint should seek prompt advice for new joint heat and swelling.

Ask whether infection needs to be ruled out before treatment, whether joint-fluid analysis or blood tests are appropriate, and what symptoms require immediate return. Ask which medicines are safe with your other conditions and how to protect the joint during recovery.