After age 40, many people notice vertical ridges—long lines from cuticle to tip—on their nails. These are usually harmless and part of natural aging. “They’re considered a natural part of the aging process,” the article explains.

As we age, keratin production slows. Keratin is the protein that gives nails their strength and smoothness. Less keratin means rougher nails and more visible ridges. Aging also causes moisture loss, making nails brittle and uneven—especially with frequent handwashing or chemical exposure.

Older adults may absorb nutrients less effectively. Deficiencies in biotin, iron, magnesium, and zinc can weaken nails and make ridges more noticeable.

Most ridges are harmless, but if nails also show discoloration, pain, swelling, or rapid changes, see a doctor. These may signal health issues like thyroid problems or poor circulation.

To care for your nails, hydrate, eat well, wear gloves when cleaning, avoid harsh nail products, and handle nails gently. Biotin supplements may help if recommended by a doctor. Vertical nail ridges are normal—but paying attention to sudden changes is important for your health.