Fingernail deformity. What gives?

Question

What causes fingernails to develop 'ridges and valleys'?
One thumb nail looks like it has a deep valley running across it (it's growing out). Some of the others look like they're too low in the moon area. I tend to pick my cuticles and maybe I did some damage by scraping near the matrix, but I'm wondering about deficiencies, side effects of medicine, etc. Do you have, or have you seen this problem?

Answer 1

many health conditions are reflected by nail changes...what you describe sounds like a result of trauma.

Answer 2

Consider a fungal infection also. A dermatologist can help.