On top of that the Chinese and Ayurvedic doctors have a whole “encyclopedia” about nail explanations, but that is not the purpose of this mail [for that you may have to travel to Beijing.]
The half moon part of the nail [where the nail goes over in the finger] is often mos clearly seen on the thumbs [see below][some people have a small half moon on most of the nails]
Sometimes this moon is red instead of white and the rest of the normal reddish nail becomes white.
This is called a Terry nail A lot has been published about Terry nails. It may show that there is a chronic liver problem but many more problems may be connected with this “reversal” of colours [red moon and white nail]
If you see this with yourself please don’t get worried and have a good night sleep but discuss it once with your doctor.
I mentioned just a small piece of physical examination in our age where we may not even look anymore at the patient but at the computer screen and thereby miss very essential features.