Many causes of knee pain, especially those related to overuse or physical activity, respond well to self-care:

• Rest and avoid activities that aggravate the pain, especially weight bearing activities.
• Apply ice. First, apply it every hour for up to 15 minutes. After the first day, apply it at least 4 times per day.
• Keep your knee elevated as much as possible to bring any swelling down.
• Gently compress the knee by wearing an ace bandage or elastic sleeve. Either can be purchased at most pharmacies. This may reduce swelling and provide support.
• Take acetaminophen for pain or ibuprofen for pain and swelling.
• Sleep with a pillow underneath or between your knees.

Call your doctor if:

• You cannot bear weight on your knee
• You have severe pain, even when not bearing weight
• Your knee buckles, clicks, or locks
• Your knee is deformed or misshapen
• You have a fever, redness or warmth around the knee, or significant swelling
• You have pain, swelling, numbness, tingling, or bluish discoloration in the calf below the sore knee
• You still have pain after 3 days of home treatment

Your health care provider will perform a physical examination, with careful attention to your knees, hips, legs, and other joints.

To help diagnose the cause of the problem, your health care provider will ask medical history questions, such as:

• When did your knee first begin to hurt?
• Have you had knee pain before? What was the cause?
• How long has this episode of knee pain lasted?
• Do you feel the pain continuously or off and on?
• Are both knees affected?
• Is the pain in your entire knee or one specific location like the kneecap, outer or inner edge, or below the knee?
• Is the pain severe?
• Can you stand or walk?
• Have you had an injury or accident involving the knee?
• Have you overused the leg? Describe your usual activities and exercise routine.
• What home treatments have you tried? Have they helped?
• Do you have other symptoms, such as pain in your hip, pain down your leg or calf, knee swelling, swelling in your calf or leg, or fever?

The following tests may be done:

• Joint fluid culture (fluid taken from the knee and examined under a microscope)
• X-ray of the knee
• MRI of the knee if a ligament or meniscus tear is suspected

Your health care provider may prescribe nonsteroidal anti-inflammatory drugs (NSAIDs) that are stronger than those available over-the-counter. If those don't help, your doctor may inject a steroid to reduce pain and inflammation.

Referrals to a physical therapist (to learn stretching and strengthening exercises) and podiatrist (to be fitted for orthotics) may be necessary. These help prevent repeated problems.

In some cases, surgery is needed. For example, if arthritis is severe, a joint replacement may be recommended. Minor ligament strain will heal with home care and torn ligaments may recover with use of a knee brace. However, for significant tears or ruptures, as well as a torn meniscus, arthroscopic knee surgery is often needed.

Recovery from ligament and meniscus problems is slow. Crutches and extended physical therapy may be needed.