9 Things Your Nails Can Tell You About Your Health

Nails can offer an important glimpse into your overall health. Having strong, healthy nails isn't just good news for your manicure: Unpleasant nail symptoms could also indicate bigger health problems.

We spoke with John Anthony, MD, a dermatologist at the Cleveland Clinic in Ohio, and Debra Jaliman, MD, a New York City-based dermatologist and author of Skin Rules, about the nail symptoms you shouldn't ignore and which ones are totally normal.

Yellow Nails

The appearance of yellow nails can occur for a few reasons. "This can happen naturally with age," said Dr. Anthony. "But it's also sometimes due to nail lacquers or acrylic nails." If you often wear acrylic nails or paint your nails and are having this problem, try taking a break from the salon and give your nails a chance to recover.

Other possible causes are smoking, which can stain nails and give them a yellowish hue, and yellow nail syndrome.

Yellow nail syndrome is a rare disorder where an individual has thick yellow nails that usually occur alongside respiratory issues and limb swelling, per the Genetic and Rare Diseases Information Center (GARD). If you think you might be experiencing yellow nail syndrome, you'll want to seek medical attention.

Dry, Cracked, or Brittle Nails

Having nails that are dry, cracked, or brittle is a common issue, and there are a few possible causes. "Soft, brittle nails can occur from dryness on the nail plate," said Dr. Jaliman. "This could be from swimming, overuse of nail polish remover, frequent dishwashing without gloves, or just from living in a low-humidity environment."

Other possible causes include chemicals (such as if you're frequently exposed to cleaning products) or aging. However, if brittle nails are an ongoing problem, talk with a healthcare provider: sometimes hypothyroidism (a condition where the thyroid works too slowly) causes this side effect too.

To soothe cracked nails, try slathering them with a super-moisturizing lotion. Like your skin, nails are absorbent, and lotion can prevent them from drying out in the future. Dr. Jaliman recommended choosing a product that contains hyaluronic acid, glycerin, or Shea butter (Health likes SheaMoisture Raw Shea Butter).

If that doesn't help, you can also try taking biotin, an over-the-counter nutritional supplement that promotes healthy nail growth. Just make sure to check in with a healthcare provider before adding new supplements to your regimen.

Clubbing

Another indicator of health via your nails is a condition called clubbing. "Clubbing of the nails—when the ends of your fingers swell and the nail becomes curved and rounded—can sometimes be a sign of liver or kidney disease," said Dr. Anthony.

Additionally, per a May 2021 Clinical Medicine article, clubbing can also occur in conditions related to lungs and the gastrointestinal tract (e.g., lung cancer, IBD). Thus, contact a healthcare provider as soon as possible if you find that you are experiencing this nail condition.

White Spots

Occasionally, you may find white spots on your nails. "Usually, those white spots are not very significant," said Dr. Anthony. The white spots are known as leukonychia, per an American Journal of Clinical Dermatology article published in February 2022.

Additionally, many people believe that white spots on nails indicate a calcium deficiency, but this isn't typically the case: "They're often the result of minor trauma, such as if you whack your finger against something, and aren't generally to do with calcium," explained Dr. Anthony.

Leukonychia is generally harmless, but it can sometimes be a sign of other serious health problems, such as liver or kidney failure. Thus, seeing a healthcare provider is the best way to determine the cause of the white spots and rule out any serious conditions.

Horizontal or Vertical Ridges

Some people may experience lines running up and down or sideways on their nails; these lines are called ridges. "I sometimes see transverse (side to side) ridges on nails," said Dr. Anthony. "This is typically the result of direct trauma to the nail or a more serious illness, in which case you'll see it on more than one nail at a time."

Horizontal ridges, also known as Beau's lines, happen due to reduced nail matrix activity, per the Clinical Medicine article, when your body is working overtime against an illness. "Your body is literally saying, 'I've got better things to do than make nails' and pauses their growth," explained Dr. Anthony.

You might also have horizontal ridges on your nails for another reason: "Horizontal lines across the nail plate can also be caused by a drug reaction, for example if the patient recently had chemotherapy," said Dr. Jaliman. MedlinePlus further noted that surgery also might be the cause of horizontal ridges.

Vertical ridges are usually a normal sign of aging. "Just like wrinkles on your face, you also get lines on your nails as you age," said Dr. Jaliman.

However, vertical ridges that are accompanied by splitting (onychorrhexis), according to a Dermatology and Therapy article published in November 2019, can be associated with alopecia areata, a condition where individuals lose their hair in different spots on the scalp.

If you're unsure of why you're experiencing nail ridges, a healthcare provider can help determine what might be the cause.

Severely Bitten Nails

Nail-biting (known medically as onychophagia) is a common habit, usually brought on by some sort of stress or even done to seek attention, according to an International Journal of Women's Dermatology article published in June 2021.

If it's excessive—say, constant biting or picking at the skin around the nails—it could be a sign of obsessive-compulsive disorder (OCD).

"Sometimes psychiatric medicine is required to treat OCD-related nail biting," said Dr. Jaliman. "A bitter-tasting compound that's polished onto the nails can help too." Ultimately, it's best to follow up with a mental health professional who can help treat symptoms of OCD.

"Spoon" Nails

"Spoon" nails refer to a very thin nail which has become concave in shape. Per the May 2021 Clinical Medicine article, spoon nails can be the result of trauma around the nail or skin diseases that lead to nail thinning.

However, spoon nails are mostly due to something else: "This is usually a sign of iron deficiency anemia," said Dr. Jaliman, who recommended speaking to a healthcare provider if you're experiencing this. "It can be treated with iron supplements." Extremely pale nails could also be a sign of iron deficiency anemia.

Pitting

According to MedlinePlus, if you have "small depressions on the nail surface," you might be experiencing nail pitting; in some cases, the affected nails can crumble or become loose and potentially fall off. Speak to a healthcare provider if your nails are covered with pits or dents, as this could be a sign that you have psoriasis, said Dr. Jaliman.

Dark Stripes or a Painful Growth

If you have black discoloration on your nails (such as black streaks) or a painful growth on the nail, see a healthcare provider immediately. According to the American Academy of Dermatology (AAD), it could be a sign of melanoma, which is a type of skin cancer.

"Melanoma that comes from the nail unit is serious and can sometimes cause black lines or stripes to appear on the nail," said Dr. Anthony. "So if you see those changes happening on your nails, it's important to see a doctor."

A Quick Review

Your nails can tell you a lot about your health. At times, the condition of your nails may be due to your lifestyle (e.g., getting manicures or smoking), or your nails can be telling you that something more serious is going on (e.g., thyroid issues). Therefore, you'll want to see a healthcare provider if you have any questions or concerns about the look or feel of your nails.