With aging, nails become dry and brittle and flat or concave instead of convex. They may develop ridges along their length. Nail color may change to yellow or gray. Brittle nails may split.

Toenails require special attention in older people and in people with diabetes ( see Foot problems in diabetes Foot problems in diabetes People with diabetes mellitus have many serious long-term complications that affect many areas of the body, particularly the blood vessels, nerves, eyes, and kidneys. (See also Diabetes Mellitus... read more ) or peripheral vascular disease ( see Foot care Foot care Occlusive peripheral arterial disease is blockage or narrowing of an artery in the legs (or rarely the arms), usually due to atherosclerosis and resulting in decreased blood flow. Symptoms depend... read more ). Such people may have poor sensation in their feet, which increases the risk of injury when they try to trim their nails. A foot doctor (podiatrist) can help care for their nails to prevent skin breakdown that can lead to infections.