Healthy Nails: Signs to Look For, Dos and Don’ts, More

It can be fun to decorate your natural nails with seasonal polishes, playful designs, and long acrylic artificial nails. Not to mention that a regular manicure can be a luxurious way to unwind and practice self-care. But you may be surprised to learn that your nails actually play an essential part in your overall health. That's why it's important to know how to take care of them — and when something may be off.

Certain changes in nails are perfectly normal. For instance, subtle white lines running from the top to the bottom of the nail are a sign of aging, says Morgana Colombo, MD, a board-certified dermatologist in Reston, Virginia. Then there are more dramatic changes in the nails' texture, color, or shape, which could point to skin flare-ups, infection, or vitamin deficiencies. So how can you tell the difference?

Here's what you need to know about achieving and maintaining healthy nails.

Healthy nails are not only aesthetically pleasing, they are also able to function a lot better than unhealthy nails.

The nail is composed of skin cells called skin appendages, according to the Institute for Quality and Efficiency in Health Care. The hard part, your fingernail itself, is technically called the nail plate, which is about 0.5 millimeters (mm) of somewhat curved keratin that attaches to the nail bed underneath it. Around the outside of the nail are the folds, which is where a thin layer of skin called the cuticle grows. On the left and right side of the nail plates are the lateral nail folds and on the lower end is the proximal nail fold.

Underneath the skin is the matrix. The matrix is what produces new keratin to push the nail plate upward and forward, which is how fingernails grow. Then there's lunula, which is the little half-moon shape at the bottom of the plate that you may be able to see through the nail plate; it's considered part of the matrix.

All these structural elements work together to create strong fingernails that can serve their purpose. "Fingernails protect the soft part of the fingers, give fingers more strength, and sharpen fine motor skills by helping you pick up things, hold on to things tighter, and scratch," Dr. Colombo explains.

Apart from their basic functions, if nails appear and feel unhealthy, it could be a sign of another condition. An estimated half of disorders can be attributed to infection, while 15 percent are due to inflammatory or metabolic illness, and 5 percent are from malignancies and pigment disturbances, research suggests.

As important as it is to spot the signs of unhealthy nails, it's also always helpful to understand what qualifies as healthy nails.

Coloring is one of the keys to understanding the health of the nail. So what is the healthiest color a nail could be? "Pinkish underneath and white at the ends," Colombo says.

Debra Jaliman, MD, a board-certified dermatologist in New York City, says a smooth nail, without any horizontal ridges or pits, is a nail that's in good condition. Nail ridges are a series of white lines across the nail, while nail pits are tiny dents.

"Nail ridges can be a sign of vitamin deficiencies or diabetes," Dr. Jaliman explains. This refers to horizontal ridges that go from left to right, as Mayo Clinic points out. Meanwhile, psoriasis and eczema can cause nail pitting.

If you have vertical ridges that run from cuticle to tip, research suggests they’re harmless. They’re a normal sign of aging, says Colombo.

Previous research suggests the mean nail thickness of healthy nails is between 0.481 and 0.397 millimeters (mm). Colombo notes that if this thickness changes in one direction or the other, thinner and more breakable or thicker, the nails are not healthy.

Generally speaking, if the color or texture of the nail changes, it's a sign of unhealthy nails. But these characteristics may alter for various reasons.

"Unhealthy nails have unusual colors," says Colombo, explaining that a yellowish, bluish, or greenish hue is out of character for nails. Essentially, anything besides the pinkish base is a sign that something's not right.

Jaliman notes that sometimes a white or yellow chalky material might sit underneath the nail plate, which is the sign of a fungal infection, also known as onychomycosis. Jaliman explains that this debris materializes when fungus breaks down the keratin in the nail. The American Academy of Family Physicians estimates that onychomycosis happens in about 10 percent of people but may be more common in older adults.

Discoloration may also be a sign of melanoma, a serious type of skin cancer. According to the American Academy of Dermatology, a brown or black band around the nail or even a darker hue around the outside of the nail could be a sign of melanoma. This dark streak might be accompanied by a bump underneath the nail.

Onychoschizia, more commonly known as nail splitting, refers to soft, brittle, thin nails, per the American Osteopathic College of Dermatology (AOCD). "A brittle nail feels rough, breaks easily, and is not smooth at the distal ends," Colombo explains.

Colombo says brittle nails can be attributed to many things, including fungal or bacterial infections, inflammatory conditions such as lichen planus or psoriasis, nutritional or vitamin deficiencies, hypothyroidism, or simply aging. But per the AOCD, onychoschizia is typically due to fingernails being too wet too often (cleaning or working with water all day) or overly dry.

Splitting down the center of the nail plate could also be a sign of melanoma or another concerning growth, as outlined by the AAD.

A nail that is too hard may suggest previous nail trauma, psoriasis, or a fungal infection, says Colombo; a nail that's too soft can't function efficiently either. Nails are often softened by chemicals that are common in household products such as cleaning supplies, laundry detergents, and even nail polish remover, per the AOCD.

If your nails do become soft, you may notice them start to peel layer by layer. This once again is likely due to external traumas such as harsh chemicals, exposure to too little or too much moisture (excessive hand-washing or wet hand activities), overbuffing the nails, too many gel or acrylic manicures, or picking off nail polish with fingernails instead of polish remover, Colombo says.

Onycholysis is a condition where the nail plate separates from the nail bed. According to the Mayo Clinic, common potential causes may include infection, injury, negative side effects from drugs or personal-care products, or even symptoms of conditions like psoriasis or thyroid disease.

The AAD also notes that a nail separating from the nail bed could also be a sign of melanoma or other concerning growth.

A healthy nail has a smooth surface. When it starts to develop rough ridges, that's when you know something's up, Jaliman says. If the ridges run from the top of the nail plate to the bottom, it's likely a natural sign of aging, Colombo points out. But if they run from side to side, something else might be at play.

"Nail ridges can be a sign of vitamin deficiencies or diabetes," Jaliman says. "For example, iron deficiency anemia can cause nail ridges." If one of these underlying concerns is the issue, once you treat it, the nails will return to their healthy, smooth, shiny state.

These can look like little pinpricks in the surface of the nail. "Nail pitting can be caused by psoriasis or eczema," Jaliman says. "When these conditions are treated, the pits will resolve."

If you want to keep your nails healthy and happy, follow these tips.

To ensure proper nail hygiene, the Centers for Disease Control and Prevention (CDC) recommends regularly cleaning and clipping fingernails to prevent dirt and germ buildup that can lead to infections. Keep them dry, too: Exposing your nails to long periods in the water can increase the risk of onychoschizia. If you have a job that requires your hands to be wet often, consider wearing gloves to protect them.

Not only is it unhygienic to put your fingers in your mouth, but when you bite your nails, you're harming the cuticles and skin around the nails. This can lead to an infection, according to the Mayo Clinic. If biting your nails has become an involuntary habit, you may want to look into alleviating some stressors. According to the American Academy of Dermatology Association, stress and anxiety are possible triggers for nail-biting.

That goes for hangnails, too. These can be a nuisance, but to avoid bleeding or the possibility of infection do not bite or tear at the hangnail. Instead, the Cleveland Clinic recommends clipping the little bit of skin with a clean nail clipper or small scissor.

When it comes to maintaining healthy nails, a good place to start is with a balanced diet. A diet that's lacking in calcium, B-complex vitamins, omega-3, folic acid, and vitamin C can lead to cracking, dry, brittle nails.

"If you get your nails done frequently, don't always use gel or powder, which can damage nails," Colombo says. "Give your nails a break from those." Too many gel or acrylic manis could lead to peeling, as Colombo points out. Even if you get a regular polish manicure, overbuffing the nails or picking off the polish can also cause peeling.

Because the fingernails are the largest skin appendage, it makes sense you’d want to moisturize them the same way you do your legs, arms, and face. According to an article published in March 2020 in the International Journal of Women's Dermatology, keeping the nails moisturized can help prevent and treat brittleness.

Colombo explains that there are all kinds of external traumas that can harm nails, from opening cans with only the fingernails to using cleaning supplies formulated with harsh chemicals. These traumas should be avoided at all costs. One way you can do this is by wearing gloves while cleaning with chemically formulated products.

Because poor nail health can be a sign of infection, a skin-care condition, or health concerns such as vitamin deficiencies or diabetes, Jaliman says it's important to keep a close eye on any changes. There's no need to panic, but awareness is always key when it comes to maintaining your health.

Supplements have played a key role when it comes to the marketing surrounding healthy nails, whether they’re claiming to benefit nail growth and strength or overall well-being. Supplements linked to nail health include collagen, vitamin E, vitamin C, vitamin A, zinc, iron, and copper. But the most popular of them all is biotin.

Biotin is a B7 vitamin found naturally in cooked eggs, salmon, avocado, pork, sweet potatoes, and seeds, according to the Harvard T.H. Chan School of Public Health. It's been touted as a solution to hair loss or weak nails. Some research has shown that biotin supplements can improve brittle nails. One small study of 44 people with brittle nails found that daily biotin supplements thickened nail plates in a majority of participants by 25 percent. Yet this study is very small, and the National Institutes of Health points out that there's still a lack of strong scientific evidence that proves the benefit of biotin supplements. Also, know that research published in April 2019 in the American Journal of Clinical Pathology suggests that consuming too much biotin may interfere with heart tests; excess biotin can similarly affect thyroid tests, other research in the June 2018 issue of Cureus notes. Talk with your healthcare team about whether a biotin supplement is right for you, and if so, at what dosage.

As for collagen supplements, a small study published in December 2017 in the Journal of Cosmetic Dermatology suggests promise for boosting nail health, but larger, more rigorous studies are needed. That research included 25 people who took a daily 2.5 gram (g) oral dose of certain bioactive collagen peptides for 24 weeks before taking four weeks off of the therapy. Researchers observed that the regimen was associated with less brittle nails in the majority of participants, and that most of the treated individuals reported being happy with the therapy results.

But once again, there's still not enough evidence to prove collagen supplements improve nail health. In fact, most oral supplements fall short when it comes to promoting nail health — unless the reason behind the nail concerns is a vitamin deficiency. One study concluded that there was no evidence to support the use of vitamins E, C, A, zinc, iron, copper, or other nutrient supplements, to improve nail health in patients without a vitamin deficiency.

If your healthcare team deems that you have a nutrient deficiency, you may benefit from a supplement. Work with them to find out which supplements you may need, and at what dose (especially in the case of biotin). Your healthcare providers can help you identify a quality, safe product. At the same time, people can also get the nutrients they need from a well-balanced diet. "Eat a proper diet with enough fruits, vegetables, protein, and iron-containing foods," Colombo suggests.

If you notice any unexplained changes in how the nail looks or feels, consider consulting your dermatologist at your next appointment. "If you have unusual discoloration, changes in texture or thickness of the nail or weird grooves or pits on your nail, see a dermatologist," Colombo says.

Slightly pink, shiny, .5 mm–thick nails are a sign of good health, but changes beyond this in appearance or texture might suggest something else. It could be simply the natural signs of aging, or it could be an infection around the nail bed. Skin-care conditions such as psoriasis and eczema can also cause changes in the nails, such as pitting.

Meanwhile, vitamin deficiencies have been shown to be the reason behind dry, brittle nails or horizontal ridges. But the most common reason for unhealthy changes in the nails are external factors such as harsh chemicals, overly wet or dry nails, or use of the nails that causes them to break, peel, or weaken.

If your changes can be linked to an external factor, it's best to avoid the activity until the nail can strengthen. If you’re unsure of where the change has come from, consult your dermatologist to make sure the changes in the nails aren't a sign of anything serious.

American Academy of Dermatologist Association (AAD)

The AAD has all kinds of resources on healthy nails. We love that their articles tend to have accompanying images and videos. For example, one that outlines how to trim your nails also has a two-minute video that shows you how. An article on whether you should see a dermatologist because of nail changes showcases pictures of these changes so you can easily compare and contrast.

DermNet NZ

With half of nail disorders being attributed to fungal infections — also known as onychomycosis — DermNet NZ provides helpful images, explanations, and treatment options. They also show a variety of images to depicting the appearance of fungal infections on different people's finger- or toenails. They then list all the ways onychomycosis can present itself in great detail, making it even easier for readers to identify their concerns before moving on to treatment options.

American Academy of Family Physicians (AAFP)

Providing resources both for the family physicians and the families they care for, the AAFP has virtual events, courses, and general evaluations that are fantastic to reference when in doubt.

National Alliance on Mental Illness (NAMI)

Stress and anxiety can make healthy nails harder to come by. The NAMI has all kinds of tools to educate and support people who want to improve their mental health. This includes a helpline for one-on-one information, peer-led family support groups, and an online library filled with information on how to decriminalize mental health — all free to access!

TLC Foundation for Body-Focused Repetitive Behaviors (BFRB)

If biting your nails has become a habit that you want to quit, you are not alone. The BFRB notes that 20 to 30 percent of the population are habitual nail-biters. Check out their resources for help. We like their pages on therapist referrals and tools for parents who may want to help their kid quit.

Academy of Nutrition and Dietetics

If you suspect the changes to your nails have been caused by a vitamin deficiency, the Academy of Nutrition and Dietetics offers information that can help you wade through the other possible signs. It outlines the typical nutrients that Americans aren't getting enough of, such as vitamin C and iron, and how people can supplement their intake.

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