Clubbing is changes in the areas under and around the toenails and fingernails that occur with some disorders. The nails also show changes.
Nail clubbing occurs when the tips of the fingers enlarge and the nails curve around the fingertips, usually over the course of years. Is a deformity of the finger or toe nails associated with a number of diseases, mostly of the heart and lungs.
Although clubbing typically is painless, it rarely may present with pain in the fingertips.