Healthy Nails: A Complete Scientific Guide

Decorating your natural nails with polish and playful designs, or getting long acrylic nails, can be fun, and a regular manicure can be a luxurious way to unwind and practice self-care. But nails actually play an essential part in your overall health. That’s why knowing how to take care of them (as well as when something’s wrong with them) is so important.

Certain nail changes 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. More dramatic changes in nail texture, color, or shape may indicate skin flare-ups, infections, or vitamin deficiencies. So how can you tell the difference?

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

Why It’s Important to Care for Your Nails

Healthy nails are not only aesthetically pleasing but they function a lot better than unhealthy nails. “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 says.

Underneath the skin is the matrix. The matrix produces new keratin that pushes the nail plate upward and forward, driving fingernail growth. Then there’s the lunula, the small half-moon shape at the bottom of the nail plate that may be visible through the nail. It's considered part of the matrix.

• An estimated half of nail disorders relate to a fungal infection, also known as onychomycosis.
• Around 20 percent of people may have brittle nail syndrome if the fingernails are thin or easily damaged, but this is twice as common in women as in men.
• Roughly 50 to 79 percent of people with psoriasis experience nail symptoms.
• Melanoma under the fingernails is rare but can be more common in people between age 50 and 60.

What Do Healthy Nails Look Like?

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

They Have a Pinkish Hue

Coloring is one of the key indicators of nail health. So what is the healthiest color a nail could be? “Pinkish underneath and white at the ends,” Colombo says.

Healthy nails are a consistent color and free of spots.

They Have a Smooth Surface

Debra Jaliman, MD, a board-certified dermatologist in New York City, says that 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.

The Nail Plate Is About 0.5 mm Thick

Colombo notes that if this thickness changes in one direction or the other, becoming thinner and more breakable or getting thicker, the nails are not healthy.

Signs Your Nails Are Unhealthy

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

Discoloration

“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.

Brittleness

Colombo notes that brittle nails can be caused by various factors, including fungal and bacterial infections, inflammatory conditions such as lichen planus and psoriasis, nutritional and vitamin deficiencies, hypothyroidism, and aging. According to the AOCD, onychoschizia typically occurs when fingernails are too wet too often (as in those who clean or work with water all day) or too dry.

Softness

Nails that are too hard may suggest previous nail trauma, psoriasis, or a fungal infection, says Colombo. Nails that are too soft can’t function efficiently either.

Peeling

If your nails become soft, they may start to peel layer by layer. This 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, too many gel or acrylic manicures, or picking off nail polish with fingernails instead of polish remover, Colombo says.

Separation From the Nail Bed

Ridges

Healthy nails have a smooth surface. When a nail 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 says. But if they run 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.

Pits

These can appear as small pinpricks on the nail surface. “Nail pitting can be caused by psoriasis or eczema,” Jaliman says. “When these conditions are treated, the pits will resolve.”

How to Care for Your Nails: 6 Dos and Don’ts

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

1. Do: Keep Your Nails Clean, Trimmed, and Dry

2. Don’t: Bite Your Nails

If biting your nails has become an involuntary habit, you may want to look into alleviating some stressors. Stress and anxiety are possible triggers for nail-biting.

3. Don’t: Overdo Manicures

“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, she says. Even with a regular polish manicure, overbuffing the nails or picking off the polish can cause peeling.

4. Do: Keep Nails Moisturized

Because the fingernails are the largest skin appendage, it makes sense to moisturize them the same way you do your legs, arms, and face.

5. Don’t: Subject Your Nails to Trauma

6. Do: Look for Troubling Signs of Poor Nail Health

Because poor nail health can be a sign of infection, a skin-care condition, or health concerns such as vitamin deficiencies and 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 for Healthy Nails: Do They Work?

Many supplement producers market products as helpful for weak or brittle nails. However, few have solid research supporting them.

• Biotin
• Collagen peptides
• Solubilized keratin methyl-sulfonyl-methane
• Choline-stabilized orthosilicic acid

If your healthcare team deems that you have a nutrient deficiency, you may benefit from a supplement. Work with them to determine which supplements you may need and at what doses (especially for biotin). Your healthcare providers can help you identify a quality, safe product.

At the same time, people may also be able to get the nutrients they need from a well-balanced diet. “Eat a proper diet with enough fruits, vegetables, protein, and iron-containing foods,” Colombo says.

When to See a Doctor

If you notice any unexplained changes in how a nail looks or feels, consider consulting your dermatologist at your next appointment.

“If you have unusual discoloration, changes in the texture or thickness of the nail, or weird grooves or pits on your nail, see a dermatologist,” Colombo says.

The Takeaway

• Healthy nails are typically pinkish with a smooth, even surface, and any significant deviations may point to underlying health issues.
• A dermatologist should assess unexplained nail changes, such as unusual colors or separation from the nail bed, as they might indicate anything from fungal infections to more serious conditions, such as melanoma.
• Moisturizing nails, avoiding trauma, and staying mindful of nail chemicals can help maintain nail health, but supplements to strengthen nails, such as biotin, often lack strong supporting evidence.
• Prioritize monitoring your nails for any color changes, brittleness, pitting, or separation, and seek professional advice promptly if these symptoms arise to ensure early intervention when necessary.