Knee swelling is the result of accumulation of excessive joint fluid. It may present with swelling, pain, stiffness or redness. Knee swelling is a common symptom of so many causes of knee conditions like,

• Osteoarthritis
• Inflammatory arthritis – Rheumatoid arthritis, Reactive arthritis
• Crystal Arthropathy – Gout, Pseudogout
• Infection – Bacterial or Tubercular
• Knee injury – ligament injury, fracture, cartilage injury, overuse
• Bleeding disorder – Haemophilia, anticoagulant therapy
• Tumour

Knee swelling can be a simple benign presentation of a chronic knee disorder like osteoarthritis or may be an acute symptom of a more debilitating condition, like infection or injury. History of other medical conditions, duration of onset of swelling, local temperature, skin colour and presence of tenderness give potential clues for cause of the swelling. Osteoarthritis, rheumatoid arthritis and tubercular infection cause gradual onset of swelling whereas bacterial infection, trauma, crystal arthropathy produces rapid swelling and is also associated with local oedema, tenderness, redness and ecchymosis. Knee aspiration can give symptomatic relief as well as provides material for pathological analysis to determine the cause of the swelling. X-ray, USG and MRI are also very useful investigations for diagnosis.

Treatment of knee swelling depends on its cause. In benign chronic swelling like in osteoarthritis requires rest, analgesic and icing. Rarely may require knee aspiration. But acute swelling due to trauma, infection and haemorrhage require emergency knee aspiration and joint fluid analysis along with aggressive cryotherapy, immobilization, analgesic and may be antibiotic.