Knee Pain
The knee is the largest joint in the body, and one of the most easily damaged. Like all joints, the knee is composed of
bones, cartilage, ligaments and tendons. The knee joint is at the junction of three bones: the femur (thigh bone),
tibia (shin bone) and patella (knee cap). Ligaments — strong, elastic bands of tissue — join bones together.
Tendons are tough cords of tissue that connect bone and muscle. Muscles, though they are not technically part of a
joint, help bend and straighten joints.
Symptoms
Common symptoms of knee damage include:
• Pain, soreness or tenderness;
• Swelling or bruising;
• Stiffness, decreased movement or locking; and
• A snap, pop or grinding feeling with movement.
The symptoms will vary depending on what caused the damage. If you injure a ligament, you may hear a popping noise
or feel your knee give out. The pain may be excruciating or
you may not be able to walk. However, after some types of
knee injury you may not feel anything until 2 to 12 hours
later, when you experience pain and swelling.
Causes
The most common cause of knee pain is an injury, which can
be caused by overuse (bursitis, tendonitis), poor exercise
habits (such as not warming
up or cooling down or inadequate stretching), a strain,
sprain, torn ligament or cartilage, a fracture or a dislocated
kneecap. Other problems that
can affect the knee include
osteoarthritis (degenerative
joint disease) and other types
of arthritis; infection; or a
problem elsewhere in the
body (like a pinched nerve), which can cause pain that is felt
in the knee.
Making the Diagnosis:
What to Expect
Doctors use several methods to diagnose knee problems. One
is a physical examination, in which the doctor will pay careful
attention to your knees, hips and legs. You may be asked to
bend, straighten or rotate your knee, as well as stand, walk or
squat so your doctor can assess knee function. Your doctor
will also take a thorough medical history, asking about your
symptoms and any injury or general health problem that
might be causing the pain. You may be asked questions about
when the pain started, how long it’s lasted, whether you ever
had it before and what it’s like — is it continuous or off-andon, dull or sharp, in your whole knee or only a certain part.
Your doctor will ask you about other symptoms, like pain in
your hip or down your leg, swelling and fever.
Diagnostic Tests
Depending on the results of the history and physical examination, you may have more tests. X-rays are the screening tool
most often used for knee pain. An MRI is rarely helpful or necessary to diagnose knee pain, but your doctor may order one:
• If he or she suspects a soft tissue injury, such as damage
to cartilage or a ligament;
• To confirm or exclude a specific condition he or she
suspects may be causing your knee pain; or
• If, after four weeks of treatment and physical therapy,
your pain hasn’t decreased.
Red Flags
The presence of a “red flag” indicates the need for further
work-up, including a more detailed physical exam, laboratory
tests and possibly x-rays or an MRI. Examples of red flags
include:
• Fever
• Chills
• Weight loss
Treatment
Prevention
Your treatment will depend on what’s causing your knee pain,
but many causes of knee pain — especially those related to
overuse or physical activity — respond well to home treatment:
Some knee problems — like those resulting from an accident —
can’t be prevented. However, following these tips may help
prevent some knee problems:
• Use RICE (Rest, Ice, Compression, Elevation) for pain and
swelling. Apply ice every hour for 15 minutes and after the
first day apply it at least four times a day. An Ace bandage or
elastic sleeve will gently compress the knee, reducing
swelling and providing support. Keeping your knee elevated
as much as possible will also bring swelling down
• Before exercising or participating in sports, warm up by
walking or riding a stationary bike, then stretching.
.• Avoid putting weight on your knee as much as possible. Use
a cane or a crutch in the hand opposite your painful knee.
Sleep with a pillow underneath or between your knees.
• Avoid sudden changes in
how hard you exercise.
Increase the pace of your
workouts slowly over time,
and take time to cool down.
• Take over-the-counter pain medication, such as acetaminophen
(e.g., Tylenol), ibuprofen (e.g., Advil or Motrin) or naproxen
(e.g., Aleve). Both ibuprofen and naproxen, as well as aspirin,
are nonsteroidal anti-inflammatory drugs (NSAIDs). If you
have been told to avoid this type of drug, call your doctor.
• Be sure to contact your doctor again if any of the following
things happen during home treatment: signs of infection or
inflammation (fever, chills, redness at the site); numbness or
tingling; your knee, lower leg or foot becomes pale or cool
or looks blue (when you’re not using ice); your symptoms
don’t improve or they become more serious or frequent.
• Keeping the quadriceps (front of the thigh) and hamstring
(back of thigh) muscles strong helps support and protect
the knee. Walking up stairs or riding a stationary bike can
strengthen these muscles.
• Wear shoes that fit properly
and are in good condition.
If your feet are flat or
pronated (roll inward), you
might need special inserts.
• Wear protective gear during sports and recreational activities.
Knee guards may reduce your risk of injury.
Additional Resources
National Library of Medicine: MedlinePlus (www.nlm.nih.gov)
Harvard Medical School Consumer Information: InteliHealth
(www.intelihealth.com)
National Institute of Arthritis and Musculoskeletal and Skin
Diseases (www.niams.nih.gov)
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