Clubbing is a condition in which the ends of the fingers and
toes swell and the nails bulge outward. The nails wrap around
the fingers or toes and look raised, curved, and shiny. Clubbing
occurs more frequently in children born with heart defects and
people with chronic heart, lung, liver, or thyroid disease. But
simple hereditary clubbing can occur without heart or lung
problems. How this information was developed to help you make
better health decisions.