Many people are curious about their fingernails, especially when they find irregularities. Pitting, ridges, spots, bands and other marks are common on nails and usually just a cosmetic issue. But dry, splitting nails, in particular, can be a nuisance and even painful. And some nail irregularities are associated with serious medical conditions.
Fingernails consist primarily of keratin, the fibrous structural protein also found in hair and skin. A nail forms at its base, starting just below the visible portion. Injury to this area can affect nail formation, as can some drugs, diseases and poisons. It takes about six to nine months for a nail to grow from cuticle to tip, but growth varies from person to person and even finger to finger. Thumb and pinky nails grow more slowly. Men’s nails grow a little faster than women’s, and the rate declines with age in both sexes. Fast-growing nails are an indication that you are well nourished, but no single food or diet promotes nail growth. You might have heard that fingernails continue to grow after people die. But that’s a myth.
Nails change over time. Just as skin tends to become drier with age, so do nails. They may become thicker, thinner or rougher, and they may develop fissures, striations and splits. Nails can also become discolored and dull and take on a yellow or gray hue or even become opaque. Meanwhile, the lunula— the white half moon seen at the base of nails—disappears in some people as they get older. Many, if not most, older people have at least one such age-related nail change.
When nails chip and crack
Brittle nails can be a sign of a medical disorder, such as thyroid disease, alopecia areata, gout, Raynaud’s disease, osteoporosis or anemia, or of malnutrition. But brittle nails are most commonly caused by normal aging and external factors, such as exposure to harsh chemicals (as in many nail products) and cosmetic nail procedures. Your nails may also become brittle if they are repeatedly wet and dried, as happens in housekeepers, health care providers and hairdressers, for example. Rarely are vitamin or mineral deficiencies to blame forbrittle nails in Americans, though excess intake of vitamin A is associated with them.
Brittle nails have a reduced ability to retain moisture, possibly because of lipid or protein abnormalities in the nail. Older people and women, especially older women, are more likely to have them, possibly because their nails grow more slowly and thus are exposed for longer periods to the things that adversely affect nails. And women, in general, use more damaging nail products.
If you notice new ridges, lines, discolorations or other irregularities on your fingernails, talk to your dermatologist or other health care provider at your next visit to rule out an underlying medical condition.
- Be cautious with manicures. Nail enamel may actually help protect against brittle nails by keeping moisture in and preventing contact with drying agents. But avoid cuticle removers and nail hardeners, which contain formaldehyde and other ingredients that can make your nails drier. Limit use of nail polish removers to no more than once a week and select one that contains acetate, which is less drying than acetone.
- Though acrylic nails and gel manicures can protect nails that are already weak or thin, taking them off is traumatic to nails, and they may have other risks, too. If you get them, either for practical or cosmetic reasons, make sure they are properly applied and maintained.
- Avoid soaps and hand sanitizers that contain the antibacterial agent triclosan, which readily removes water from the nail. Hand sanitizers with alcohol are also drying. Wear gloves when washing dishes, doing household chores or gardening, or if you are exposed to chemicals occupationally.
- To treat brittle nails, soak them for 10 minutes a day in an emollient that contains petrolatum, lanolin, lecithin or mineral oil. Other helpful ingredients are urea, glycerin and alpha-hydroxy acids (lactic acid, for example), which increase water retention. Many products specifically designed for fingernails contain a combination of these ingredients. You can ask your health care provider or pharmacist to suggest one.
- Eat a well-balanced diet that provides adequate protein and other nutrients. There’s no evidence that vitamins, minerals or other supplements are of benefit, unless you have a deficiency. Though gelatin has long been recommended for healthy nails, there are no data to support its use. Nails don’t even contain gelatin. Two old studies suggested that biotin may help treat brittle nails, but they were small and had no control group.