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Why does my knee click?

Your knees are among the hardest working joints in your body. Think about it, they have to bear your full weight every day and are used every time you stand up, sit down, squat, bend, go upstairs and play sport. It’s no surprise that you might feel a little click or pop every once in awhile!

The scientific name for these noises is crepitus, and unless you feel pain when it happens, it’s usually nothing to worry about. One of the main reasons people pay attention to crackling joints is that this is often incorrectly claimed to cause arthritis. You’ll be pleased to hear there’s no scientific evidence at all to support this theory.

Of course, it’s worth knowing exactly why your knees might be clicking, as there are a few scenarios where a visit to the doctor may be necessary. Let’s take a look at them.

Womans knee clicking


Let’s face it, we all know what happens when the body releases gas at high speed - there tends to be noise involved! That’s essentially what’s happening each time you bend your knees.

Gas bubbles form in the spaces between your joints, and when you close these joints quickly, for example by getting up, running or jumping, these bubbles are quickly set free. It’s perfectly natural and nothing to be concerned about.

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Runner’s Knee

If your knee clicks when you straighten it or walk upstairs, this could be a sign of a condition known as Runner’s Knee. It’s one of the most common medical problems affecting runners and is actually caused by weak leg muscles.

If your thighs are much larger than your hamstrings, or vice versa, this can throw your knee joint out of line. What happens next is that your kneecap starts to rub against your thighbone, causing irritation that can either be a dull ache or sharp, stabbing pain.

Either way, it’s probably best you don’t skip leg day next time you hit the gym!

Runner’s Knee can also be caused by wearing the wrong footwear. Your chosen trainers might not be right for your running style, so it’s worth investigating the possibility of using orthotics (specially made insoles) to ensure your knee joint has enough support while you’re jogging.


Now, we know we said that clicking your joints doesn’t cause arthritis, and that is correct. However, the opposite can be true - in other words, a clicking knee can be a symptom of arthritis.

While often associated with old age, arthritis can affect anyone. There are thought to be around 10 million sufferers in the UK. Osteoarthritis (the most common type) occurs through wear and tear that leaves your cartilage too thin to do their job properly, while rheumatoid arthritis is an autoimmune condition that causes your cartilage to swell.

While arthritis can’t be cured, you may be prescribed painkillers to manage your discomfort, or referred to a physiotherapist who will help slow down the progress of the condition.

Worn or torn cartilage

The knee is a complicated joint. Your kneecap is in the middle of your thigh bone (femur), shin bone (tibia) and calf bone (fibula). Each of these bones is covered by a layer of cartilage that absorbs any impact on the joint and ensures these bones don’t rub together and cause irritation.

If this cartilage becomes damaged, it can mean your bones come into contact with each other. This is likely to result in an unpleasant grinding sensation. One of the most common causes of cartilage damage is a sports injury, which can tear the tissue and be quite painful.

Minor cartilage injuries may get better on their own, particularly with plenty of rest and the occasional ice pack. However, you may also need treatment such as a knee brace or painkillers. If the problem is serious, surgery may be required to fully repair your knee.

How should you react to a bad knee?

While knee clicking on its own is usually not an issue, you should see a doctor as soon as you feel pain in your knee. An early diagnosis will mean you can treat the problem before it gets any worse, or make the necessary lifestyle changes to make injuries less likely.

Your doctor will advise you how to respond to your specific injury, such as resting or taking medication, but there are also some general steps you can take to prevent these kind of injuries from occurring. This is particularly important if you’ve injured your knee in the past.

  • Losing weight - This will make sure there’s less pressure on your knees.
  • A gentle exercise plan - If you’ve had problems before, you may need to tone down your previous exercise plan to avoid a repeat injury, or at least start off slowly to build your joint back up again.
  • Choose soft surfaces to run on - Each time your foot hits the floor, your knee is the joint that absorbs the shock. Running on concrete naturally puts more pressure on the knee that running on grass or sand, so this is something to bear in mind.
  • Try a different sport - If you’ve had a serious knee injury, it might not be possible to continue playing sports that require you to twist, turn or make a sudden movement. You might want to try a more sedate sport if you want to stay active.

Concerned about your knee clicking? See a doctor

If you’re worried about the noises coming from your knee, our GPs will be able to give you peace of mind. Book an appointment at a time to suit you and use your smartphone, tablet or desktop device to chat to a doctor about your symptoms.
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