If you're paying attention to your fingernails only when you're trimming them, biting them or getting a manicure, it's time to give them a little more consideration. Changes in your nails' texture or shape can indicate mild or even serious health problems you might not otherwise be aware of.
My five-year-old son, for example, recently developed indented, horizontal ridges near the bottom of his fingernails and toenails. All were about in the same place, just around cuticle-level. Mysterious, but not painful or inflamed, the ridges appeared without any other signs or symptoms of illness.
A brief search on the Internet, though, followed by a trip to his pediatrician's office, provided deeper insights into what his fingernails and toenails were telling me: about six weeks earlier, he had apparently suffered an infection or illness of some kind -- possibly even strep. The only symptom visible then was peeling skin on his hands (I had assumed his skin had been irritated by working with paper mache or some other material at preschool).
Whatever the illness was, though, it was strong enough to interfere with the normal growth of his nails. Because fingernails grow by about 1 millimeter every 10 days (toenails grow a little more slowly), that interference became visible as horizontal ridges -- known as Beau's lines -- on my son's nails several weeks later.
Fortunately, he's now healthy as can be, and his doctor says we'll probably never know what he had that caused the nail problem. The lesson I've learned, though, is that paying attention to your nails can be one more way of tracking your health and keeping healthy.
Following are some nail conditions to watch for, and what they might indicate (remember, always check with a doctor first rather than trying to treat yourself without knowing for sure what the problem is):
Beau's lines (indented ridges that cross one or multiple nails horizontally): They indicate a past illness or trauma that interfered with normal nail development. The lines might also be a sign of Raynaud's disease, which can cause your extremities to feel numb or cold when stressed or exposed to cool temperatures.
Clubbed nails: Nails that become clubbed are more convex (outwardly curved) than normal, and curl down at the end to meet the fingertip. While the cause of clubbing isn't clear, it's a sign of low oxygen levels in the blood, possibly caused by a heart or lung problem. It can also indicate inflammatory bowel disease.
Yellow nails: While not always a sign of illness, nails with a yellowish discoloration can signal a possible respiratory disease.
Pitted nails: Nails with small, irregular indentations can be a sign of psoriasis, a skin condition.
Spoon-like nails: Marked by sunken, concave (like a spoon) nails, this condition points to anemia caused by an iron deficiency.
Terry's nails: This condition occurs when nails look opaque and whitish, with a dark band of coloration near the tip. While it sometimes occurs as people age, it can also indicate congestive heart failure, liver disease, diabetes or malnutrition.
Nail separation: When a nail becomes loose and pulls away from the nail bed underneath, the cause can be anything from an injury or infection to thyroid disease, psoriasis or a reaction to drugs, acrylic nails or other substances that have been used on the nails.
To see more examples of nail problems that might indicate an underlying health cause, check out this slide show on the Mayo Clinic's Website, or visit the American Family Physician's guide to Nail Abnormalities.
