Forwarded.

Forwarded as received. Checked as deserved.

Viral health forwards, held against the best evidence. Free. No ads. No trackers.

Chest pain, breathlessness or collapse right now? Call 108 or 112.

Claim 10 · Joints

Knuckle cracking: "it causes arthritis".

A relaxed hand in profile with small arcs near the knuckles A simple outline of a relaxed hand seen from the side, fingers loosely curled, with a few small arcs by the knuckles where the crack is heard. Every study that has looked finds no link between knuckle cracking and arthritis.

As forwarded

"Cracking your knuckles causes arthritis."

A universal parental warning, recently re-circulated in Indian media fact-checks (The Week, 13 October 2025) [S1]. Reach figure: not available. Reach not available

Verdict

Unsupported

Every study that has looked, including a 215-person radiograph study and a doctor who cracked one hand for 50 years, finds no link between knuckle cracking and arthritis; the sound is gas bubbles in joint fluid.

What the evidence says

Supported

The best-designed study. A retrospective case-control of 215 adults aged 50–89 who had a recent right-hand X-ray (135 with hand osteoarthritis, 80 without). Knuckle crackers made up 20%. OA prevalence was 18.1% in crackers versus 21.5% in non-crackers (P=0.548); after adjusting for age, sex, family history and heavy labour, cracking was not associated with OA (P=0.626). Cumulative "crack-years" at each joint also showed no association. Conclusion: habitual knuckle cracking, including total duration and cumulative exposure, does not appear to be a risk factor for hand OA. [S2]

Supported

The famous self-experiment. Donald Unger cracked the knuckles of his left hand at least twice a day for about 50 years and used his right hand as a control; he found no arthritis in either hand. The same article notes earlier studies: 28 nursing-home residents (Swezey 1975) and 300 outpatients over 45 (1990) found no excess arthritis among crackers. [S3]

Supported

Mechanism and residual concerns. Harvard Health states knuckle cracking "probably won't raise your risk for arthritis", explains the pop as bubbles in synovial fluid, and notes two residual cautions: chronic cracking may reduce grip strength, and there are at least two published reports of injuries sustained while trying to crack knuckles. [S4]

What to do instead

  1. Nothing is required; if cracking is painless it can be ignored.

  2. Joint pain, swelling, morning stiffness lasting over 30 minutes, or loss of grip: see a doctor; these are symptoms of arthritis regardless of cracking habits. [S4]

  3. Do not force or yank joints to produce a crack; there are published reports of injuries. [S4]

Share card

Sources

  1. S1
    The Week. Fact check: does cracking your knuckles every day cause arthritis?Circulation only; not evidence · 13 October 2025
    theweek.in/news/health/2025/10/13/fact-check-does-cracking-your-knuckles-every-day-cause-arthritis.amp.html
  2. S2
    deWeber K et al. Knuckle cracking and hand osteoarthritis. Journal of the American Board of Family Medicine 2011;24:169 (n=215).Tier 3-level primary study · 2011
    jabfm.org/content/24/2/169
  3. S3
    Scientific American. Crack research (describing Unger, Arthritis & Rheumatism 1998, n=1).Tier not graded in the research file · primary letter not opened
    scientificamerican.com/article/crack-research
  4. S4
    Harvard Health. Does cracking knuckles cause arthritis?Tier 4 · dated 6 July 2020
    health.harvard.edu/staying-healthy/does-cracking-knuckles-cause-arthritis

Tiers are as graded in the research file. "Circulation only" sources document that a claim circulates and are never cited as evidence. Where a primary paper could not be opened, the page says so in the Honest note.

Reviewed by

Medical review: being arranged

Every evidence sentence on this page traces to the sources listed above, but no registered physician has yet signed it off. When one has, their name, registration number and date of review will appear here. Until then, read this page as a sourced guide, not as medical advice: for any symptom, call 108 or 112, or see a doctor.

Corrections

No corrections yet. Write to [email protected].