Nail clubbing

Nail clubbing, also known as digital clubbing or clubbing, is a deformity of the finger or toe nails associated with a number of diseases, anomalies and defects, some congenital, mostly of the heart and lungs. When it occurs together with joint effusions, joint pains, and abnormal skin and bone growth it is known as hypertrophic osteoarthropathy.

Clubbing is associated with lung cancer, lung infections, interstitial lung disease, cystic fibrosis, or cardiovascular disease. Clubbing may also run in families, and occur unassociated with other medical problems.

Clubbing has been recognized as a sign of disease since the time of Hippocrates.