Q: I have dark vertical lines on some of my fingernails. Overall, I'm healthy. What causes this condition?
A: You probably have a harmless condition called melanonychia.
It features brown or black streaks of the nail. It occurs because of increased pigmentation.
Melanonychia is more common in older people and darker-skinned people. It can also be seen after radiation therapy, after ultraviolet light exposure, while taking certain medications, during pregnancy, and with certain medical conditions. Melanonychia is rare in children.
Moles in the nail can also appear as dark streaks.
It is very important to have a dark streak in a nail examined by a doctor because melanoma, a dangerous form of skin cancer, can also appear as a dark nail streak. This type of melanoma is called "subungual melanoma." It will sometimes show a dark pigmentation on the skin at the edge of the streaked nail. This is called "Hutchinson's sign" and can be helpful in diagnosis. In some cases, your doctor may want to do a biopsy.
Rebecca Campen, M.D., J.D., is an Assistant Professor of Dermatology at Harvard Medical School and former Deputy Director of the Harvard/Massachusetts General Hospital Cutaneous Biology Research Center (CBRC). She currently serves as senior advisor to the CBRC and divides her time between clinical practice of dermatology at the Massachusetts General Hospital and private practice in Savannah, Georgia. Dr. Campen is the author of two books for medical students and residents, Going Into Medical Practice and Blueprints in Dermatology.
be well, feel better
Showering and brushing your teeth every day isn't enough. These stealth sources of body odor, whether from food, meds or health conditions, can sneak up on you.
See how many you can check off so far.
You know the health rules: floss daily, get enough sleep, eat lots of fruits and veggies, etc.
This nutrient is notoriously hard to get from food—so you need to be extra vigilant and keep an eye out for these clues you may not be getting enough.
Just because you can't taste it doesn't mean belly-bloating sodium isn't there. Here's how to spot the salt that's hiding in your diet.
Alison Sweeney's secrets to sneaking in fitness, making time for fun, and going after your big dreams.
These simple substitutions cut calories painlessly and can add up to a big difference on your scale.
Need help sticking to your diet? Start snacking on these good-for-you treats.