Have you noticed thin vertical lines running from the base to the tip of your fingernails as you’ve gotten older? You’re not alone. Many people begin to see these changes after age 40. While they are usually harmless, vertical nail ridges can occasionally signal underlying health issues. So, what causes them, and when should you be concerned? Vertical ridges — also known as longitudinal striations — are raised lines that run from the cuticle to the nail tip. They can vary in depth and number, becoming more noticeable with age. For most people, these ridges are a natural part of getting older. Just as skin loses elasticity and hair turns gray, nails also undergo structural changes. The production of keratin — the protein that makes up nails — can slow or become uneven over time, leading to changes in nail texture.

The most common cause after age 40 is the natural aging process. As the body’s cell renewal slows, nail matrix cells (which form new nail tissue) may produce keratin unevenly, creating ridges. Dehydration also plays a role; aging nails often become drier and more brittle, emphasizing ridges. Frequent hand washing or exposure to cleaning chemicals can worsen dryness. Nutritional deficiencies, particularly in biotin, iron, zinc, or magnesium, can further weaken nails. Additionally, certain health conditions — such as thyroid disorders, poor circulation, or rheumatoid arthritis — may contribute to changes in nail texture, making ridges more noticeable or severe.

Vertical ridges are usually harmless, but if they appear alongside nail discoloration, splitting, pain, or swelling, it’s best to consult a doctor. These symptoms can indicate fungal infections or, rarely, melanoma. To care for aging nails, moisturize regularly, stay hydrated, eat a nutrient-rich diet, and use gentle nail care techniques. Biotin supplements may help strengthen nails, but it’s important to seek medical advice first before starting any new supplement routine.