What is knee pain?

Your kneecap (patella) is a thick, round bone that covers and protects the front (anterior) part of your knee joint. It moves along a groove in your thighbone (femur) as part of the patellofemoral joint. A layer of cartilage surrounds the underside of your kneecap. This layer protects it from grinding against your femur.

When this cartilage softens and breaks down, it can cause knee pain. This is partly due to repetitive stress. The stress irritates the lining of the joint. This causes pain in the underlying bone.

Knee pain is very common. It's even more likely to happen in highly active people who put a lot of pressure on their knees, such runners. It affects people assigned female at birth more often. You may also hear this type of knee pain called patellofemoral pain, anterior knee pain, runner's knee, or jumper's knee.

What causes knee pain?

Several different overlapping causes can lead to knee pain. Some of these include:

  • Overuse of the knee joint
  • Misalignment of the patella and surrounding structures
  • Damage to small nerves in the region
  • Damage to a ligament-like structure (retinaculum) that holds the patella in place
  • Degeneration of the bone under the cartilage
  • Inflammation in the soft tissues around the patella
  • Injury

Who is at risk for knee pain?

You might be at greater risk of knee pain if you:

  • Exercise heavily, or have recently increased the intensity of your workouts
  • Have a body mass index greater than 25
  • Have poor alignment of your patella
  • Walk with your feet turned overly out or in
  • Have weakness in nearby muscle groups, such as weak inner quad or hip adductor muscles
  • Have too much tightness in nearby muscle groups, such as tight hamstrings or iliotibial band
  • Have a recent history of injury to the area
  • Were assigned female at birth

You can’t change many of these risk factors. Losing weight and correcting excess muscle tightness or muscle weakness may help reduce your risk.

What are the symptoms of knee pain?

Knee pain is marked by a dull, aching pain in the front of the knee in the area under and around the kneecap. This pain may start quickly or slowly. Your pain might be worse when you squat, run, or sit for a long time. You might also sometimes feel like your knee is giving out. You might have symptoms in 1 or both of your knees.

How is knee pain diagnosed?

Your healthcare provider will begin with a health history. They will ask about your other health problems as well as your current symptoms. Describe any activities that make your knee pain worse.

You’ll have a complete knee exam. This will include tests of your range of motion, strength, and sore areas of your knee. Your provider will also assess your knee alignment. They will need to rule out other possible causes of your knee pain. These can include arthritis or instability.

Often, you won't need any more tests. If your diagnosis is unclear, you might need imaging tests to rule out other possible causes. These tests may include an X-ray or MRI.

How is knee pain treated?

Your healthcare provider might suggest a few different treatment strategies to help ease your symptoms. These might include:

  • Not doing activities that make your pain worse for a while, and slowly returning to activity.
  • Icing the outside of your knee when it causes you pain.
  • Taking over-the-counter pain medicines.
  • Wearing a knee brace or taping your knee to support it.
  • Wearing special shoe inserts to help keep your feet in the correct alignment.
  • Practicing special exercises to stretch and strengthen the muscles around your hip and your knee. Your provider or physical therapist can show you how.

These steps help most people manage knee pain. Your provider might advise surgery if you still have significant symptoms after 6 months of trying these other therapies. Depending on the underlying cause of your knee pain, your provider might suggest 1 of several surgical options, such as surgically realigning your kneecap. You can discuss all of your surgical options with your orthopedic surgeon.

How can I prevent knee pain?

In some cases, you can prevent knee pain. To help prevent a flare-up of knee pain, do the following:

  • Regularly do all the exercises your healthcare provider or physical therapist advises.
  • Support your knee as advised by your provider or physical therapist.
  • Ease up on your training when needed and increase your training slowly,
  • Have an expert check your running stance or your stance for your sporting activity,
  • Learn how to correctly stretch before and after exercise,
  • Replace your running shoes regularly.

When should I call my healthcare provider?

If your symptoms don't start to get better after a few weeks of treatment, see your healthcare provider. You may have a different kind of problem with your knee.

Key points about knee pain

  • Knee pain is a common health condition. Irritation to the tissue around the kneecap causes the condition. Too much repetitive stress makes knee pain much more likely to happen.
  • Your healthcare provider will likely be able to diagnose you with a simple health history and physical exam.
  • Most people respond to treatment such as pain medicines, ice, stretching and strengthening exercises, and not doing certain activities for a while.
  • In rare cases, some people need surgery to treat their condition.
  • Taking simple steps, such as doing your physical therapy exercises, may help prevent your symptoms from coming back.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

  • Know the reason for your visit and what you want to happen.
  • Before your visit, write down questions you want answered.
  • Bring someone with you to help you ask questions and remember what your provider tells you.
  • At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.
  • Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are and when they should be reported.
  • Ask if your condition can be treated in other ways.
  • Know why a test or procedure is recommended and what the results could mean.
  • Know what to expect if you do not take the medicine or have the test or procedure.
  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your provider if you have questions.