Clubbing of the fingers

In a normal finger, the length of the perpendicular dropped from point A to point B should be greater than a similar line from C to D. In clubbing, the relationships are reversed; that is, the distance C-D is greater than the distance A-B. The other important change is the angle described by A-C-E. In the normal finger, this is usually <180°, whereas in clubbing, it is >180°.