When the distal phalanges (bones nearest the fingertips) of corresponding fingers of opposite hands are directly opposed (place fingernails of same finger on opposite hands against each other, nail to nail), a small diamond-shaped "window" is normally apparent between the nailbeds. If this window is obliterated, the test is positive and clubbing is present. Epidemiology
The exact frequency of clubbing in the population is not known. A 2008 study found clubbing in 1%, or 15 patients, of 1511 patients admitted to a department of internal medicine in Belgium. Of these, 40%, or 6 patients, turned out to have significant underlying disease of various causes, while 60%, or 9 patients, had no medical problems on further investigations and remained well over the subsequent year. History
At least since the time of Hippocrates, clubbing has been recognized as a sign of disease. The phenomenon has been called "Hippocratic fingers". See also
Clubbed thumb (unrelated congenital deformity)


== References ==
Classified may refer to:

General
Classified information, material that a government body deems to be sensitive
Classified advertising or "classifieds"

Music
Classified (rapper) (born 1977), Canadian rapper
The Classified, a 1980s American rock band featuring Steve Vai
Classified Records, an American record label

Albums
Classified (Bond album), 2004
Classified (Classified album), 2013
Classified (Sweetbox album), 2001
Classified, by James Booker, 1982

Songs
"Classified", by C. W. McCall from Wolf Creek Pass, 1975
"Classified", by the Orb from Metallic Spheres, 2010
"Classified", by Pete Townshend from the compilation Glastonbury Fayre, 1972
"Classifieds", by the Academy Is... from Almost Here, 2005

Other media
Classified (1925 film), an American silent film
Classified: The Edward Snowden Story, a 2014 Canadian film
Classified: The Sentinel Crisis, a 2005 video game for the Xbox

See also
Classification (disambiguation)
Classifier (disambiguation)