As people pass 40, fingernails often develop vertical ridges, known as “longitudinal striations,” which run from the cuticle to the tip. These lines are usually a normal sign of aging rather than a medical problem. While they may affect appearance, they are generally harmless and can simply reflect the body’s natural changes over time.

One main reason for these ridges is the gradual slowdown in “keratin” production, the protein responsible for nail strength and structure. As the body produces less keratin with age, the nail surface becomes less smooth and more uneven. At the same time, nails and skin lose moisture, making nails drier and more brittle. Everyday exposure to water, soaps, and cleaning products can further dry the nails and make ridges more visible.

Nutrition also plays a role in nail health. As the body ages, it may absorb vitamins and minerals less efficiently, which can contribute to mild deficiencies. Nutrients like biotin (Vitamin B7), iron, magnesium, and zinc are important for maintaining strong and healthy nails. When intake or absorption is low, nails may become thinner, weaker, and more prone to surface changes like ridges.

In most cases, vertical ridges are not a concern, but certain symptoms should not be ignored. Changes such as discoloration, thickening, splitting, or pain around the nail may point to underlying issues. In some situations, nail abnormalities can be linked to conditions like thyroid disorders, circulation problems, or infections, so sudden or unusual changes should be checked by a healthcare professional.

Supporting nail health involves simple habits. Staying hydrated, maintaining a balanced diet, and protecting hands from harsh chemicals can help. Regular moisturizing, gentle nail care, and avoiding strong removers like acetone can reduce dryness. With consistent care and attention, nails can remain healthier and stronger, even as natural aging leads to visible changes.