Health Encyclopedia

Knee pain

Alternative Names

Pain - knee

Common Causes

Knee pain usually results from overuse, poor form during physical activity, not warming up or cooling down, or inadequate stretching. Simple causes of knee pain often clear up on their own with self care. Being overweight can put you at greater risk for knee problems.

Knee pain can be caused by:

Arthritis -- including rheumatoid, osteoarthritis, and gout
Baker's cyst -- a fluid-filled swelling behind the knee that may accompany inflammation from other causes, like arthritis
Bursitis -- inflammation from repeated pressure on the knee, such as kneeling for long periods of time, overuse, or injury
Connective tissue disorders such as lupus
Dislocation of the kneecap
Iliotibial band syndrome -- a hip disorder related to injury of the thick band that runs from your hip to the outside of your knee
Infection in the joint
Knee injuries -- may cause bleeding into your knee, which worsens the pain
Tendinitis -- a pain in the front of your knee that gets worse when going up and down stairs or inclines
Torn cartilage (a meniscus tear) -- pain felt on the inside or outside of the knee joint
Torn ligament (ACL tear) -- leads to pain and instability of the knee
Strain or sprain -- minor injuries to the ligaments caused by sudden or unnatural twisting

Less common conditions that can lead to knee pain include the following:

Home Care

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 health care provider if

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

What to expect at your health care provider's office

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 doctor 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?
Would you say that the pain is severe?
Does it feel bruised?
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, like pain in your hip, pain down your leg or calf, knee swelling, swelling in your calf or leg, fever?

The following diagnostic tests may be performed:

Fluid drawn from the knee and analyzed
X-ray of the knee
MRI of the knee if a ligament or meniscus tear is suspected

Your doctor 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.

Prevention

Increase your activity level slowly over time. For example, when you begin exercising again, walk rather than run.
Always warm up before exercising and cool down afterward. Stretch your quadriceps and hamstrings.
Replace your sports shoes often. Get good advice about proper footwear for your foot shape and mechanics. For example, if you pronate (land on the outside of your heel and turn your foot inward), consider anti-pronation footwear.

References

Labropoulos N, Shifrin DA, Paxinos O. New insights into the development of popliteal cysts. Br J Surg. 2004; 91(10): 1313-1318.

Fithian DC. Fate of the anterior cruciate ligament-injured knee. Orthop Clin North Am. 2002; 33(4): 621-636, v.

Review Date:7/25/2007
Reviewed By:Andrew L. Chen, M.D., M.S., Orthopedist, The Alpine Clinic, Littleton, NH. Review provided by VeriMed Healthcare Network.

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