Symptoms

The location and severity of knee pain may vary, depending on the cause of the problem. Signs and symptoms that sometimes accompany knee pain include:

• Swelling and stiffness
• Redness and warmth to the touch
• Weakness or instability
• Popping or crunching noises
• Inability to fully straighten the knee

When to see a doctor

Call your doctor if you:

• Can't bear weight on your knee or feel as if your knee is unstable or gives out
• Have marked knee swelling
• Are unable to fully extend or flex your knee
• See an obvious deformity in your leg or knee
• Have a fever, in addition to redness, pain and swelling in your knee
• Have severe knee pain that is associated with an injury