Ever looked at a chipped, brittle, or black-lined nail and wondered why it looks that way? Well, it turns out that nail health is closely associated with how well your body is functioning in other areas.

“For the general population, nail health is most often an indicator of poor nutritional intake or poor digestion,” explains Dr. Sara Norris, a naturopathic doctor based in Los Angeles. “Brittle, weak, and peeling nails are the most common concerns I see in my practice and these symptoms are more often the result of a poor diet than of systemic disease.”

Dr. Mark Benor, clinical assistant professor of family medicine at Keck School of Medicine, agrees: “My job is reassuring people that their nail issues usually don’t bespeak a serious underlying illness,” he explains. “The family medicine clinic is full of patients with nail findings of no significance outside of the anxiety they create.”

Healthy nails are considered to be smooth with no discoloration, but if there’s something amiss with the texture and color of yours, this guide can help you find a fix. Plus, we’ll tell you which symptoms might warrant a talk with a healthcare professional.

Brittle

splitting nail against pink background

Rough, splitting nails that may also crack easily are one of the most commonly reported nail problems. Officially called onychoschizia, brittle nails are usually caused by repeated wetting and drying of your fingernails, so you should use gloves when getting your hands wet, such as when doing dishes.

In some cases, brittle nails might also be a sign of hypothyroidism or iron deficiency.

The fix: You can try applying lotions that contain alpha hydroxy acids or lanolin and wearing gloves while washing dishes or doing other water-heavy tasks.

Read more about the potential causes of brittle nails.

Soft or weak

Soft fingernail against pink background

These nails break easily or bend before snapping. Soft nails might be caused by overexposure to moisture or chemicals — think detergent, cleaning fluids, nail treatments, and nail polish remover.

Weak nails might also be associated with a deficiency in B vitamins, calcium, iron, or fatty acids.

The fix: Avoid having chemicals around your nails. Go natural to give your nails a chance to recover. Norris advises against iron supplements unless you know you’re deficient. Instead, start taking a multivitamin that includes calcium and B vitamins.

Read more about soft or weak nails.

Peeling

peeling fingernail against pink background

This is likely caused by external trauma to the nail itself — by using your nail as a tool, pressing into the nail too firmly or removing acrylic nail polish. Nails can also peel if you soak your hands too long in sudsy water.

Here’s a trick to figuring out whether it’s an internal or external cause: Are your toenails also peeling? If so, it might be an internal cause, such as iron deficiency. If not, it’s probably external.

The fix: If you think it’s internal, trying adding iron-rich foods to your diet. If the cause is external, keep your nails moisturized by applying lotion after any activity that might dry them out. Talk with a healthcare professional if symptoms continue, especially if you also notice peeling on your toenails.

Read more about peeling nails.

Ridges

nail with ridges against pink background

Have you ever noticed ridges that look like little horizontal or vertical waves on your fingernails? Vertical ridges generally appear later in life and run from the tip of your fingernail to the cuticle. As long as they aren’t accompanied by other symptoms such as changes in color, they’re usually aren’t a cause for concern.

Horizontal ridges, also called Beau’s lines, may be a sign of kidney disease or another underlying condition.

The fix: For vertical ridges, you can gently buff the surface of your nail to smooth them. For horizontal lines, see a healthcare professional to find the underlying cause.

Read more about nail ridges.

Yellow

Yellow nails are relatively common, and usually caused by one of two factors: an infection or a reaction from a product you’ve been using, such as nail polish.

In rare cases, yellow might be a sign of a larger issue, including thyroid conditions, psoriasis, or diabetes.

The fix: Your new nails should grow in clear again, but there are many natural treatments such as tea tree oil or vitamin E to help tackle infections. A multivitamin might also help with this. Talk with a healthcare professional if you don’t notice improvement after a few weeks.

Read more about yellow nails.

Black lines

Also called a splinter hemorrhage, black lines (which can appear brown or dark red) look like splinters. They can appear multiple times. The most likely cause is a trauma to your nail, such as accidentally slamming a door on your finger.

In rare cases, the lines could be a sign of an underlying issue, including psoriasis, endocarditis, or nail melanoma.

The fix: The lines should disappear over time as your nail grows if they’re due to an injury. But if you don’t notice any change over a few weeks, talk with a healthcare professional, especially if you notice any other symptoms, like inflamed skin, night sweats, or bleeding in the nail.

Read more about black lines on nails.

White spots

“Scattered white spots on the nails, which usually start appearing around middle-school age, can signify a zinc deficiency,” explains Norris.

The fix: Give your nails a break from polish or other products and allow the nail to grow. If the spots remain or reappear, talk with a healthcare professional.

Read more about white spots on nails.

No half moons

No half moons at the base of your nail? Most of the time, this means nothing and they could just be hidden under your skin.

If they seem to have disappeared, it could be a sign of:

The fix: Usually, not having half moons isn’t anything to be concerned about, but you’ll want to talk with a healthcare professional if they start turning red or disappear after being visible for some time.

Read more about half-moon nails.

IssueCommon causeTreatment options
Brittle nailsFrequent wetting and dryingApply lotions containing alpha hydroxy acids or lanolin.
Soft or weak nailsOverexposure to moisture or chemicalsKeep nails natural and unpolished; consider taking a multivitamin containing B vitamins and calcium.
PeelingInjury or iron deficiencyKeep nails moisturized; add iron-rich foods to diet.
RidgesAging (vertical) or underlying condition (vertical)Gently buff nails; talk with a healthcare professional.
Yellow nailsInfection or reaction to productGive nail time to grow out (it should come in clear); apply tea tree oil or vitamin E if infected.
Black linesInjuryGive nail time to grow out.
White spotsInjury, infection, allergic reaction, mineral deficiencyGive nail time to grow out; avoid using nail polish; talk with a healthcare professional.
No half moonsNothing — not everyone has them!Talk with a healthcare professional if accompanied by weight changes, dizziness, changes in mood, or other unexplained symptoms.

While most nail issues resolve on their own or with home treatments, some may be a sign of an underlying condition requiring treatment.

It’s best to talk with a healthcare professional if the changes in your nails are accompanied by:

  • fatigue
  • weight loss
  • weakness
  • inflamed skin
  • excessive thirst
  • night sweats
  • swelling
  • heart palpitations
  • dizziness
  • symptoms of depression

You’ll also want to talk with a healthcare professional if you notice horizontal lines.

“Our bodies are smart so when we’re low in vitamins and minerals, our nails and hair will show it,” explains Norris.

Eating a variety of whole foods — fruits, vegetables, whole grains — will usually get you all the vitamins, minerals, and nutrients your nails need.

You can also take a multivitamin, but Norris advises against a one-a-day tablets: “It’s difficult for our bodies to digest large compressed tablets.”

Instead, she suggests looking for a product that comes in soft-gel capsules. Why? Capsules are typically made from gelatin. According to Norris, it’s much easier for our bodies to break down gelatin to get to the vitamins and minerals within the product.

You can also try biotin and horsetail supplements. If you do go the biotin route, Norris advises to discontinue use 2 weeks prior to having any lab work done since it may interfere with results.

If your nails are acting up on their own, without any additional symptoms, it’s usually not a cause for concern. But if you notice any other unexplained symptoms, consider talking with a healthcare professional about potential causes. Most underlying causes of nail issues are easy to treat once they’re identified.