Ask Dr. K: Dehydration is often the culprit causing brittle nails

Brittle nails usually result from dehydration. Your nails may be dehydrated if you live in a dry climate, frequently wash and dry your hands, or if you often use nail polish remover.

Here are some things you can do to keep your nails healthy and combat dehydration:

— Avoid long hot baths or showers.

— Always moisturize your hands after washing and drying them.

— Use a moisturizer (petroleum jelly is fine) on your hands and nails at bedtime.

— Avoid prolonged exposure to cold, dry weather. Wear gloves outdoors.

— Trim your nails regularly to keep them short and smoothly rounded at the tips.

— Protect fingernails from injury. Wear gloves if you are working with your hands.

— Don’t bite your nails or the protective cuticles around them.

— Use a nail hardener or clear polish to strengthen the nails.

— Don’t use nail polish remover more than twice a month.

— If you get manicures, stick with reputable nail salons that sterilize instruments. Better yet, bring your own.

— Trim your nails only after soaking them or after a bath or shower. They’ll be less likely to split.

— File your nails in one direction only, and use a fine emery board or file.

— In hot weather or when exercising, stay well hydrated.

The vertical lines or “ridging” you mentioned is a natural part of nail growth. Ridging tends to happen more as we get older, and I don’t know of any way to eliminate it.

Finally, don’t fall for the many myths and misconceptions about nail care. For example, eating gelatin or soaking your nails in it will not make your nails healthier or longer.

I recall the first time a patient asked me about her brittle nails. Particularly since this patient also had serious heart and lung disease, I wondered why she was bringing it up. I surely hadn’t been taught anything in medical school about problems with fingernails.

A senior colleague gave me some wise advice: “People care about their appearance — a lot. Some people care more about their appearance than about their life-threatening illnesses. Don’t dismiss those concerns.”

Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.