Originally Posted by mrsD

I've read alot of sites about fingernails. This topic comes up frequently, including for ME.

The vertical ridges seem to be more or less described as part of aging. They also show up with hypothyroid issues (I have both situations.)

I also have a finger that I pinched doing garden/rock work, and it has a HUGE vertical ridge with a depression now about 2 millimeters wide. I guess I damaged the growth plate. This finger is also the same that was smashed by my Dad accidently in a car door when I was small. So I guess it was destined to be ruined forever!
That was a MESS and painful as I remember.

The horizontal ridges can be from arsenic poisoning, or nutritional deficiency (sometimes comes after a surgery or trauma). They are called Beau's lines.

I found a really good site...let me see if I can retrieve it now....
searching....
Here it is:
http://hooked-on-nails.com/naildisorders.html
The pictures on this site are the best I have found, over the years. The vertical ridges are at the bottom of the page.

Women typically worry more about this subject than the guys do. (obviously)

Autoimmune issues can cause the nail to separate from the nail bed in some cases. Fungus will do that too.