It’s been said that nails are a barometer of your overall health, and that is certainly true even when your condition is simply getting older. Like hair, nails undergo changes over time, due to disease, internal processes in the body as it ages, nutritional deficiencies, or external factors like long-term exposure to chemicals or ultraviolet light.

The changes nails may undergo over time involve growth rate, texture, thickness, shape or contour, and color.

Growth Rate

Close up of multicolor fingernail polish on woman's hands — Echo/Getty Images

Nail growth slows slightly over time. On average, fingernails grow about 3 mm (0.1 inches) per month; toenails only a third of that, or 1mm (0.04 inch) per month.

As early as the age of 25, that rate slows by about 0.5% per year. So by the age of 85, your fingernails may only be growing 2 mm in length per month.

Nail Texture

With age, nails may become brittle and prone to breaking. Repeated wetting and drying, or exposure to harsh cleaning chemicals or cosmetics like cuticle and nail polish removers, can worsen the problem.

More serious brittleness can cause ridges along the length of the nail and fragmenting of the nail tips. Conditions like anemia, hardening of the arteries (atherosclerosis) and hormonal problems can be a cause, so consult your health provider if you notice significant texture changes in your nails.

Nail Thickness

Nails may become thicker or thinner with age. Skin conditions like psoriasis and eczema can also result in thicker nails.

Fungal infections, which account for about half of all nail disorders and are more common in the elderly, can cause nail thickening and discoloration. The scientific term for a nail fungal infection is onychomycosis.

Toenails are particularly vulnerable because shoes provide a warm, moist environment for fungus to grow. Being male, smoking, and certain diseases, like diabetes and immune deficiency conditions, can predispose someone to develop nail fungal infections.

Treatments for fungal nail infections include oral or topical (applied to the nail) antifungal preparations, which may need to be administered for a period of months. Choosing the right medication will depend on other prescriptions you may be taking (to avoid drug interactions) and the severity of the infection.

Nail Contour

How curved your nails are may change as you age. A dramatic shape change with very rounded nails is clubbing, a sign of long-term oxygen deprivation. It can occur with a variety of cardiovascular, endocrine, or gastrointestinal diseases, and should be investigated by your doctor.

Pressure from too-tight shoes or foot deformities that pushes a nail inward can cause ingrown toenails. Though more common in younger people, ingrown nails in the elderly can cause substantial pain and walking problems. Simple treatment involves soaking the foot to ease the ingrown nail out using small pieces of cotton. Minor surgery to remove a narrow strip of the nail is usually more effective at preventing future ingrowth.

Nail Color

Over time, nails may become discolored, turning slightly yellowed, gray, generally pale, or opaque. Fungal infections can also cause discoloration.

One type of color change involves dark stripes or ridges along the length of the nail. The medical term for this is longitudinal melanonychia. Darker-skinned people, such as Hispanics and African Americans, often develop longitudinal melanonychia as they age. The stripes are made up of the same pigment, or melanin, that accounts for the color of your hair.

In some cases, however, dark ridges can signal a more serious condition. The stripe may constitute a melanoma, or malignant skin cancer, under the nail. This is more likely when it appears on only one digit—typically the big toe, thumb, or index finger.

Bowen's disease, a form of skin cancer, may occasionally show up as a darker stripe on the nail. More typically, it appears on the skin of the hand. A dark stripe may also be caused by a splinter hemorrhage, or bruise beneath the nail, which in the elderly is usually due to minor trauma to the nail and resolves on its own.

Ask Your Doctor

While many of the nail changes that occur with age are minor, some can signal more serious health problems like heart and lung disease, anemia, liver and kidney problems, and diabetes. See your family physician or dermatologist if you have any concerns.

How Your Fingernails Change as You Age