Fingernail clubbing is a sign of underlying lung or heart disease.

Is it true that fingernail clubbing is a sign of underlying lung or heart disease?

Partly. Several sources associate digital clubbing with serious internal illnesses, including lung cancer, bronchiectasis and cyanotic congenital heart disease, but others link it to liver disease, hyperparathyroidism or no identifiable cause, so the evidence only partly supports the claim that it signals underlying lung or heart disease.

Verdict: CONTESTED PARTIAL · 5 sources for, 2 against · Last checked 3 Oct 2026

The private library was unavailable for some searches in this check. Missing library results are not evidence against the claim.

M, M. (2007). Exploring the cause of the most ancient clinical sign of medicine: finger clubbing.. doi.org. https://doi.org/10.1016/j.semarthrit.2006.11.004

O, E., R, D., & S, S. (1981). Prospective study of periostitis and finger clubbing in primary biliary cirrhosis and other forms of chronic liver disease.. doi.org. https://doi.org/10.1136/gut.22.3.203

Digital clubbing - PMC Lock. (n.d.). pmc.ncbi.nlm.nih.gov. https://doi.org/10.4103/0970-2113.102824

CJ, D. & JF, M. (1987). Megakaryocytes and platelet clumps as the cause of finger clubbing.. doi.org. https://doi.org/10.1016/s0140-6736(87)91132-9

X, V. & B, R. (2008). Prevalence, aetiologies and significance of clubbing in a department of general internal medicine.. doi.org. https://doi.org/10.1016/j.ejim.2007.05.015

KS, S., CF, L., & RD, A. (1998). Digital clubbing and lung cancer.. doi.org. https://doi.org/10.1378/chest.114.6.1535

Nenad, P., Zorica, Š., & G., T. (2012). Digital clubbing as an unusual complication of the secondary hyperparathyroidism associated with atypical neutrophils: a case report. zenodo.org. https://doi.org/10.5281/zenodo.12704710