Nails aren't only for decorating with fun colors. They help protect our fingers and toes from injury and make it easier to grip things.
Our nails can also tell us a lot about our overall health, according to Dr. Shari Lipner, a dermatologist at Weill Cornell Medical Center who specializes in treating nail disorders.
Nutritional deficiencies, autoimmune disorders, and even heart and liver disease can all manifest in the nails.
Lipner previously spoke to TODAY.com about why it's important to take breaks from polish to examine the health of your nails and monitor for any new changes in the shape, color or texture.
Many nail irregularities are benign, but they can be a sign of an underlying health issue. There's one nail health red flag in particular that people should never brush off, Lipner says.
Dermatologist Tip of the Day: Never Ignore A Sudden, Dark Vertical Line on the Nail
If you notice a new dark brown or black vertical line on your nail, don't ignore it, Lipner says.
Also called "melanonychia," these dark streaks on the fingernails or toenails are caused by a deposit of pigment cells, aka melanin, in the nail matrix, per the Cleveland Clinic.
These lines can be normal, especially among people with darker skin — however, there is a possibility that something serious is brewing.
Why It Matters
“Rarely, it can also be a sign of a nail cancer called a nail unit melanoma,” says Lipner. It’s a type of acral lentiginous melanoma, a skin cancer that originates in the nail matrix. It often starts out as a thin black or brown nail streak.
It’s more of a concern if you only have one line or if only affects one nail, TODAY.com previously reported.
Not all streaks are cancerous. In most cases, a line on the nail is harmless and due to aging, previous injury or a benign growth.
However, it's impossible to tell on your own, which is why it’s important to get checked out by a dermatologist or bring it up at your annual skin check — especially if the line appears suddenly or it’s changing.
Although this nail cancer is rare among the general population, it's one of the most common types of melanoma among people with darker skin. It's usually caused by genetics, not UV exposure, and often goes unnoticed until it's in the later stages and more aggressive, per the Aim at Melanoma Foundation.
Reggae superstar Bob Marley died at 36 from acral lentiginous melanoma, which started in his big toenail.
How to Get Started
It's important to be able to examine your natural, bare nails regularly — which means taking breaks from manicures and pedicures. “When people use polish continuously, they may not be aware of defects,” Lipner says.
Aim to do a nail check about once a month, Lipner recommends. Look for any changes or irregularities in the nails, cuticles and surrounding skin.
In addition to streaks or discoloration of the nails, check for any growths, pitting or dents, ridges, weakness or nail lifting. Not all nail changes are worrisome or a sign of a serious problem, but they may still require treatment from a dermatologist.
TODAY’s Expert Tip of the Day series is all about simple strategies to make life a little easier. Every Monday through Friday, different qualified experts share their best advice on diet, fitness, heart health, mental wellness and more.
