The term applied to the thickening and broadening of the fingertips – and, less commonly, the tips of the toes – that occurs in certain chronic diseases of the lungs and heart. It is due to interstitial OEDEMA especially at the nail bed, leading to a loss of the acute angle between the nail and the skin of the finger. Clubbing is associated with lung cancer, EMPYEMA, BRONCHIECTASIS and congenital cyanotic heart disease.