Clubbing may result from chronic low blood-oxygen levels. This can be seen with cystic fibrosis, congenital cyanotic heart disease, and several other diseases. The tips of the fingers enlarge and the nails become extremely curved from front to back.
Review Date: 5/10/2013 Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.