Knee pain may start suddenly, or it may be a long-term problem. You may have pain on the side, front, or back of your knee. You may have knee stiffness and swelling. You may hear popping sounds or feel like your knee is giving way or locking up as you walk. You may feel pain when you sit, stand, walk, or climb up and down stairs.
What increases my risk for knee pain?
- A strain or tear in ligaments or tendons
- A leg fracture or knee dislocation
- Overuse of your knee
- Osteoarthritis, rheumatoid arthritis, or gout
- An infection, tumor, or cyst in your knee
- Shoes that are not supportive, or training on a hard surface
- Sports that involve jumping or pivoting on your knee
How is the cause of knee pain diagnosed?
Your healthcare provider will examine your knee and ask about your symptoms. Tell your provider when the pain started and what you were doing at the time. Describe the pain, such as sharp, throbbing, or achy. Tell your provider about any knee injury or surgery you had. You may need any of the following:
- MRI, CT, or ultrasound pictures may show an injury, fracture, or tumor.
- Blood tests may be used to check the level of inflammation in your blood. The tests may also show signs of infection.
- Arthroscopy is a procedure to look inside your knee joint with an arthroscope. An arthroscope is a flexible tube with a light and camera on the end. A knee arthroscopy is usually done to check for disease or damage inside your knee. These problems may be fixed during the procedure.
How is knee pain treated?
Treatment will depend on the cause of your pain. You may need any of the following:
- NSAIDs help decrease swelling and pain or fever. This medicine is available with or without a doctor's order. NSAIDs can cause stomach bleeding or kidney problems in certain people. If you take blood thinner medicine, always ask your healthcare provider if NSAIDs are safe for you. Always read the medicine label and follow directions.
- Acetaminophen decreases pain and fever. It is available without a doctor's order. Ask how much to take and how often to take it. Follow directions. Read the labels of all other medicines you are using to see if they also contain acetaminophen, or ask your doctor or pharmacist. Acetaminophen can cause liver damage if not taken correctly. Do not use more than 4 grams (4,000 milligrams) total of acetaminophen in one day.
- Prescription pain medicine may be given. Ask your healthcare provider how to take this medicine safely. Some prescription pain medicines contain acetaminophen. Do not take other medicines that contain acetaminophen without talking to your healthcare provider. Too much acetaminophen may cause liver damage. Prescription pain medicine may cause constipation. Ask your healthcare provider how to prevent or treat constipation.
- Steroid injections may be given into your knee. Steroids reduce inflammation and pain.
- Surgery may be used for some injuries, such as to repair a torn ACL.
What can I do to manage my symptoms?
- Rest your knee so it can heal. Limit activities that increase your pain. Do low-impact exercises, such as walking or swimming.
- Apply ice to help reduce swelling and pain. Use an ice pack, or put crushed ice in a plastic bag. Cover it with a towel before you apply it to your knee. Apply ice for 15 to 20 minutes every hour, or as directed.
- Apply compression to help reduce swelling. Use a brace or bandage only as directed.
- Elevate your knee to help decrease pain and swelling. Elevate your knee while you are sitting or lying down. Prop your leg on pillows to keep your knee above the level of your heart.
Prevent your knee from moving as directed. Your healthcare provider may put on a cast or splint. You may need to wear a leg brace to stabilize your knee. A leg brace can be adjusted to increase your range of motion as your knee heals.
What can I do to prevent knee pain?
- Maintain a healthy weight. Extra weight increases your risk for knee pain. Ask your healthcare provider how much you should weigh. He or she can help you create a safe weight loss plan if you need to lose weight.
- Exercise or train properly. Use the correct equipment for sports. Wear shoes that provide good support. Check your posture often as you exercise, play sports, or train for an event. This can help prevent stress and strain on your knees. Rest between sessions so you do not overwork your knees.
When should I seek immediate care?
- Your pain is worse, even after treatment.
- You cannot bend or straighten your leg completely.
- The swelling around your knee does not go down even with treatment.
- Your knee is painful and hot to the touch.
When should I contact my healthcare provider?
- You have questions or concerns about your condition or care.
- 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
Some examples of mechanical problems that can cause knee pain include:
- Loose body. Sometimes injury or degeneration of bone or cartilage can cause a piece of bone or cartilage to break off and float in the joint space. This may not create any problems unless the loose body interferes with knee joint movement, in which case the effect is something like a pencil caught in a door hinge.
- Iliotibial band syndrome. This occurs when the tough band of tissue that extends from the outside of your hip to the outside of your knee (iliotibial band) becomes so tight that it rubs against the outer portion of your thighbone. Distance runners and cyclists are especially susceptible to iliotibial band syndrome.
- Dislocated kneecap. This occurs when the triangular bone that covers the front of your knee (patella) slips out of place, usually to the outside of your knee. In some cases, the kneecap may stay displaced and you'll be able to see the dislocation.
- Hip or foot pain. If you have hip or foot pain, you may change the way you walk to spare your painful joint. But this altered gait can place more stress on your knee joint and cause knee pain.
Types of arthritis
More than 100 different types of arthritis exist. The varieties most likely to affect the knee include:
- Osteoarthritis. Sometimes called degenerative arthritis, osteoarthritis is the most common type of arthritis. It's a wear-and-tear condition that occurs when the cartilage in your knee deteriorates with use and age.
- Rheumatoid arthritis. The most debilitating form of arthritis, rheumatoid arthritis is an autoimmune condition that can affect almost any joint in your body, including your knees. Although rheumatoid arthritis is a chronic disease, it tends to vary in severity and may even come and go.
- Gout. This type of arthritis occurs when uric acid crystals build up in the joint. While gout most commonly affects the big toe, it can also occur in the knee.
- Pseudogout. Often mistaken for gout, pseudogout is caused by calcium-containing crystals that develop in the joint fluid. Knees are the most common joint affected by pseudogout.
- Septic arthritis. Sometimes your knee joint can become infected, leading to swelling, pain and redness. Septic arthritis often occurs with a fever, and there's usually no trauma before the onset of pain. Septic arthritis can quickly cause extensive damage to the knee cartilage. If you have knee pain with any of the symptoms of septic arthritis, see your doctor right away.
Patellofemoral pain syndrome is a general term that refers to pain arising between the kneecap and the underlying thighbone. It's common in athletes; in young adults, especially those whose kneecap doesn't track properly in its groove; and in older adults, who usually develop the condition as a result of arthritis of the kneecap.
A number of factors can increase your risk of having knee problems, including:
- Excess weight. Being overweight or obese increases stress on your knee joints, even during ordinary activities such as walking or going up and down stairs. It also puts you at increased risk of osteoarthritis by accelerating the breakdown of joint cartilage.
- Lack of muscle flexibility or strength. A lack of strength and flexibility can increase the risk of knee injuries. Strong muscles help stabilize and protect your joints, and muscle flexibility can help you achieve full range of motion.
- Certain sports or occupations. Some sports put greater stress on your knees than do others. Alpine skiing with its rigid ski boots and potential for falls, basketball's jumps and pivots, and the repeated pounding your knees take when you run or jog all increase your risk of knee injury. Jobs that require repetitive stress on the knees such as construction or farming also can increase your risk.
- Previous injury. Having a previous knee injury makes it more likely that you'll injure your knee again.
Not all knee pain is serious. But some knee injuries and medical conditions, such as osteoarthritis, can lead to increasing pain, joint damage and disability if left untreated. And having a knee injury — even a minor one — makes it more likely that you'll have similar injuries in the future.
Although it's not always possible to prevent knee pain, the following suggestions may help ward off injuries and joint deterioration:
- Keep extra pounds off. Maintain a healthy weight; it's one of the best things you can do for your knees. Every extra pound puts additional strain on your joints, increasing the risk of injuries and osteoarthritis.
- Be in shape to play your sport. To prepare your muscles for the demands of sports participation, take time for conditioning.
- Practice perfectly. Make sure the technique and movement patterns you use in your sports or activity are the best they can be. Lessons from a professional can be very helpful.
- Get strong, stay flexible. Weak muscles are a leading cause of knee injuries. You'll benefit from building up your quadriceps and hamstrings, the muscles on the front and back of your thighs that help support your knees. Balance and stability training helps the muscles around your knees work together more effectively.
And because tight muscles also can contribute to injury, stretching is important. Try to include flexibility exercises in your workouts.
- Be smart about exercise. If you have osteoarthritis, chronic knee pain or recurring injuries, you may need to change the way you exercise. Consider switching to swimming, water aerobics or other low-impact activities — at least for a few days a week. Sometimes simply limiting high-impact activities will provide relief.