As you’ve gotten older, have you noticed thin vertical lines running from the base to the tip of your fingernails? If so, you’re not alone. Many people begin to notice these changes after age 40. Most of the time, they’re harmless, but in some cases, they can indicate underlying health problems. So what causes vertical ridges—and when should you be concerned?

Understanding Vertical Nail Ridges

Vertical ridges, also  called longitudinal striations  , are raised lines that extend from the cuticle to the tip of the nail. They can vary in depth and number and often become more noticeable with age.

Just as skin loses elasticity and hair turns gray, nails undergo structural changes over time. The production of keratin—the protein that forms nails—can slow down or become uneven, resulting in ridges.

Main causes after the age of 40

1. Natural aging process

The most common cause of vertical ridges is simply aging. As we age, the body’s ability to regenerate skin cells slows. The same thing happens with the nail matrix (the base of the nail), which can produce keratin unevenly, leading to ridges.