To Your Health

Q. My nails were never great, but the last two years I have really suffered from nails that are too soft to hold up to daily wear and tear. I also notice some ridges developing. What can I do to improve them?

A. Fingernails reveal a lot about your health and sometimes even people who take good care of their nails have problems with pliable and easily broken fingernails. As early as 400 BC, Hippocrates taught that the nails reflect the condition of the whole body. Fingernails protect the sensitive ends of the fingertips and a healthy nail should be strong and smooth with a pink nail bed underneath, indicating a healthy blood supply.

Nails are composed of a protein called keratin, and the nail rests on the nail bed, a layer of special skin cells. The nail bed serves only to support the nail, as it grows outward from the nail root. Fingernails require about 4-6 months to grow out while toenails grow more slowly, requiring 8-12 months to grow out. Growth rates vary with age, season, and nutritional status. Diseases can change nail growth rate and appearance.

Very soft nails may reflect protein malnutrition, endocrine problems, or chronic arthritis. Soft nails have also been blamed on repeated contact with strong detergents. Each time your nails get wet they swell, then shrink again when they dry off. This swelling/shrinking cycle when repeated often enough, leaves your nails fragile.

Protein malnutrition can occur even when your dietary protein intake is generous if you cannot digest protein well. Protein digestion starts in the stomach under acid conditions, so if you lack stomach acid the breakdown of protein into absorbable amino acids may be hindered. You might want to check with a physician about ways to measure the adequacy of your stomach acid.

Among the classic signs of thyroid insufficiency are soft nails and horizontal ridging. Since you have both of these indicators, ask your physician to check your thyroid status. Taken together with thinning hair and overall feelings of fatigue, poor nails may be indications of an under-functioning thyroid.

"Beau lines" are transverse, often white, ridges that appear a few weeks after a brief episode of severe stress or trauma, such as high fever, shock, or heart attack. They result from decreased cell division in the nail bed causing a thin nail plate and are visible until the affected area of the nail has grown out. Nail growth returns to normal with the resolution of the systemic cause. A severe bout of arthritis might cause both soft nails and the ridges.

Soft nails and horizontal ridges by no means exhaust the connections between health problems and nail manifestations. To mention just a few:

Spoon-shaped nails can be associated with iron deficiency.

Clubbing of nails may indicate chronic respiratory or heart problems.

Overlarge moons at the base of the nail could indicate an overactive thyroid.

Yellow fingernails are sometimes found after long-term use of tetracycline.

White, crumbly nails are often the result of a fungus infection.

Yellow or brown "oil" spots on the nails may signal eczema or psoriasis.

Finally, a brown or black streak that begins at the base of the nail and extends to its tip could be a clue to a potentially dangerous melanoma. See your health care provider immediately.

So keep a sharp eye on your nails; they are a conspicuous window to your inner workings.