If the nails are brittle or have splits or jagged edges along with vertical ridges, it may indicate onychorrhexis, notes WebMD. Onychorrhexis often results as a side effect of lichen planus, a skin rash. It can also indicate an underactive thyroid gland or anemia.
On their own in otherwise healthy nails, vertical ridges in the nail that run from the cuticle to the tip of the nail are normal and a result of aging. These ridges do not indicate a health problem or injury and are harmless. Vertical ridges increase in prominence and number with age. By contrast, lines that run vertically on the nail may indicate a health issue and require evaluation by a medical professional, reports WebMD.