You get up from the chair and your knee makes a sharp sound. You roll your shoulders and hear a series of cracks. Your neck, when you turn it, almost always clicks. And the question is always the same: are my joints wearing out?
The honest answer is neither "it's nothing" nor "go straight for an X-ray". It is a middle ground worth understanding, because it tells you exactly what to look for.
Crepitus is common, and this has been measured
In a study that compared clinical examination with radiographic examination in 775 knees, crepitus was the most frequent physical finding of all: present in 25% of cases, ahead of tenderness (15%), bony swelling (12%) and pain on flexion (10%) (Concordance between clinical and radiographic evaluations of knee osteoarthritis, Aging Clinical and Experimental Research, 2018).
One knee in four among those examined. This is not an anomaly: it is something joints do.
But it is not "nothing" either, and anyone who tells you so is oversimplifying
Here most articles stop at "it's just air, don't worry". The full data from the same study is more interesting: crepitus, together with tenderness, bony swelling and pain on flexion, was associated with an increased risk of femorotibial osteoarthritis. And an overall clinical score, meaning more signs present together, had a strong association (odds ratio 12.5).
The correct reading is this: the noise on its own is not a diagnosis, but it is not a signal without meaning either. What matters is the company it keeps.
Cracking your fingers does not cause arthritis
This, on the other hand, is a worry you can set aside. A review of the clinical anatomy of joint cracking, published in Clinical Anatomy in 2018, gathered the literature on the mechanism and the clinical associations of cracking your knuckles, and the conclusion is clear: the evidence for a link with arthritis comes mainly from observational studies that failed to demonstrate that association (Let's get a hand on this: Review of the clinical anatomy of "knuckle cracking", Clinical Anatomy, 2018).
On the mechanism there is agreement on one thing: a bubble forms in the joint fluid. On how exactly it forms, the debate has been open for more than a century.
The question that separates the two cases
It is not "does it crack?". It is: does it crack and nothing else, or does it crack and something else too?
Noise on its own. No pain, no swelling, no locking, the joint does everything it did before. It reduces after a few movements, and gets worse after hours of immobility or in the cold. This picture, in the vast majority of cases, is mechanical and trivial.
Noise with something else. Pain during or right after the noise; swelling; heat; the feeling that the joint locks or gives way; loss of movement compared with before. Here the noise stops being the main symptom and the rest is what needs to be assessed.
A practical detail: if the noise appeared after a trauma, or if it comes with giving way, do not wait to see whether it goes away.
Why it is worse in the morning
After hours of immobility the tissues are stiffer, the joint fluid is less evenly distributed and the surfaces glide less smoothly. A few movements and a few minutes are enough for the noise to reduce, and it is precisely this behaviour that suggests it is not signalling structural damage: damage does not warm up away in three minutes.
The same goes for the cold and for periods when you move less.
What to do, if it does not hurt
Little, and in this direction: move more and with more variety, not less. The reflex of protecting a joint that makes noise leads to using it less, using it less makes it stiffer, and stiffer makes more noise. It becomes a cycle that feeds itself.
If the noise bothers you in a specific movement, such as squatting, stairs or getting up from a chair, it is worth looking at how you do it: often it changes much more by changing your foot placement or your control of the movement than by doing exercises for the joint itself.
If one particular joint cracks
- The knee: knee that makes noise, causes and when to worry.
- The shoulder: shoulder that clicks, causes and remedies.
When you need a doctor
- Noise with pain that does not go away, or that gets worse week by week.
- Swelling, heat or redness of the joint.
- The joint locks or gives way.
- It appeared after a trauma.
- Morning stiffness lasting more than half an hour and affecting several joints: that picture should be checked by a doctor, because it is not mechanical.
What we can do
If the noise is isolated, the most useful thing is often to clear up the doubt and get moving again what you were avoiding. In the free twenty-minute first consultation we look at how the joint that makes noise moves and tell you which of the two cases you are in, or whether the right next step is something else.
