13 Things Your Nails Might Be Telling You About Your Health

We talk a lot about how to keep our nails healthy from an aesthetic perspective, but have you ever thought about what your nails might be saying about your overall health? Experts say that there are a handful of medical conditions — some serious, some not — that can show up on our fingertips. To save you the trouble of Googling those nail abnormalities (because, ew), we’ve asked the experts to break down what our nails are trying to tell us about our health.

What a ‘Normal’ Nail Looks Like

Let’s be clear: we’re here to educate, not to help you self-diagnose. But, before we can talk about nail health warning signs, we need to establish what’s normal and expected. Our nails (both fingernails and toenails) are made up of layers of a protein called keratin — the same substance found in our hair and our skin’s outermost layer. The visible part of your nails is actually dead, which is why cutting them doesn’t hurt.

The Anatomy of the Nail:

New nail cells begin growing inside the matrix (the hidden part of the nail beneath the bottom edge) and push the old ones through your skin as they grow out. Healthy nails are uniform in color and texture — without pits, grooves, spots, or discoloration. Although the size and shape of the nail bed and nail thickness varies from person to person, nails should be gently convex and extend outward off the tips of the fingers.

What Nails Say About Our Health

“Healthy nails equal a healthy body,” says Morgan Rabach, MD, a board certified dermatologist in New York City. Nails can be indicators of both medical conditions and skin disorders. “Nails can be the first sign of an underlying medical condition, like thyroid disease, cardiovascular disease, pulmonary disorders, certain cancers, and malnutrition,” she explains. “There are also many skin disorders, like psoriasis and eczema, where there are nail findings.”

The appearance of the nails can also be an indication of how well we take care of ourselves. “Our nails are a direct reflection of our nutrition,” says Megan Rigby, PNP, DNP, a nutritionist and wellness coach in Phoenix, AZ. As she explains it, what you’re putting into your body is a direct reflection of what you see on the outside. “How we nourish and hydrate our body is directly seen in our overall nail health,” she shares.

What Your Nails May Be Telling You

Chances are, you’ve experienced some of the more typical nail issues (think: dry, brittle nails, particularly during winter or in very arid climates). Depressions, pits, bruises, or white spots can all occur as a result of injury to the nail plate or nail bed. And, as we age, vertical ridges along the nails become increasingly present. Fungal infections (more common on the toenails), which cause nail discoloration and malformation, are another common nail condition that isn’t typically too concerning — unless, of course, you don’t treat it.

So, is there a rule of thumb (pun intended) to determine if your nail issue is relatively harmless or something more serious? “Any change in shape, growth pattern, or color of your nail should be sought out by a board certified dermatologist,” Dr. Rabach cautions. Here, we overview some of the signs that can show up on our fingertips:

1. Pale Nails

Nails that are unusually pale can indicate a lack of hemoglobin (a protein that carries oxygen in the blood) in red blood cells or a lack of red blood cells in general. This could be caused by a variety of health conditions, including anemia, congestive heart failure, liver disease, and malnutrition.

2. White Nails

Nails that are mostly white with a rim of color are also known as ‘Terry’s Nails’ — named after the doctor who first described them in 1954. They are associated with liver conditions like hepatitis and cirrhosis, as well as various kidney diseases and human immunodeficiency disease.

3. Yellow Nails

Although commonly caused by a fungal infection (see above) or polish-stained nail plates, yellow nails can also be a sign of chronic lung disease (more common in smokers), severe thyroid disease, diabetes, a vitamin deficiency, or psoriasis. If the condition is accompanied by nail malformation, respiratory abnormalities, and lymphedema (swelling), it may be an indication of an extremely rare (and possibly genetic) disorder known as yellow nail syndrome.

4. Blue Nails

If nails take on a bluish hue, that’s an indication that they’re not getting enough oxygen. This condition, known as cyanosis, could simply be the result of cold exposure. If it persists, it could be a reflection of a larger circulatory issue. Common causes include deep vein thrombosis, Raynaud’s phenomenon, lymphedema, heart failure, venous or arterial insufficiency, severe hypotension (low blood pressure). It could also be a sign of lung trouble, like emphysema, asthma, pneumonia, or a pulmonary embolism (a blood clot in the lung).

5. White Spots

Contrary to popular belief, white spots or lines appearing in the nails aren’t the result of a calcium deficiency. The condition, technically known as leukonychia, is most commonly associated with injury to the nail bed — either from an accident or manicure/pedicure damage. Sometimes, it can be a sign of malnutrition, but not a lack of calcium.

6. Dark Lines or Spots Underneath Nails

Unless caused by an acute injury, a dark streak running vertically under nails should be examined by a doctor right away, as it could be a sign of a type of skin cancer known as subungual melanoma. If left unchecked, it can spread to your lymph nodes. Sometimes, black or brown lines can be the result of other conditions like heart problems, lupus, vasculitis, fungal infection, psoriasis, Raynaud’s syndrome, or lung, kidney, or circulatory problems.

7. Spoon Nails

Also known as koilonychia, this abnormality causes the nail to have a concave, scooped out appearance that can be deep enough to hold a drop of liquid. Spoon nails can be caused by iron deficiency anemia, says Dr. Rabach. Underlying causes include malnutrition, celiac disease, gastrointestinal bleeding, and a liver condition called hemochromatosis, which causes an overload of iron in the body.

8. Cracked, Brittle, or Split Nails

Nails that are dry, peel easily, or seem brittle or thin may be damaged from weather or from too much nail polish. But they may also be showing signs of something more serious. The condition — technically known as onychoschizia — could be the result of vitamin deficiencies, anemia, or hypothyroidism.

9. Slow-Growing Nails

Fun fact: nails grow more slowly in wintertime. But stress (both physical and psychological) can slow down nail growth, as well. Studies show that elevated levels of the stress hormone cortisol can cause changes in our nails, which can be exacerbated by nervous, damaging habits like rubbing fingers over our nail plates.

10. Dented Nails

“Beau’s lines — a horizontal dent that goes through the middle of the nail — can be a sign of high fever or other infections,” Dr. Rabach says. First diagnosed by French physician Joseph Beau in 1846, these depressions (formed as a result of trauma to the area beneath the cuticle) can also indicate vascular disease, diabetes, and vitamin deficiency.

11. Pitted or Rippled Nails

If nails take on an orange peel appearance, it could be the result of an injury, or it might be a sign of psoriasis — especially if the pitting is accompanied by changes in shape, thickness, or color. Pitted nails are also a sign of eczema, or certain autoimmune conditions like alopecia areata and inflammatory arthritis.

12. Clubbed Nails

This condition is characterized by an enlargement of the fingertips and a curving of the nails around the edge of the fingers. “Clubbing is a sign of diseases where being well-oxygenated is a problem, like lung cancer or asthma, or heart diseases,” Dr. Rabach shares.

13. Puffy, Red Cuticles

If the skin surrounding the nail becomes red, inflamed, or painful, it could be a sign of an infection known as paronychia. Swelling in the nail bed in combination with small, discolored spots and/or nail malformation can also be indicative of lupus.

The Takeaway

“Nails are an important clue to internal disease and could be a presenting sign,” Dr. Rabach says. It is also important to remember that nails can have intrinsic disease, like melanoma. So, if you are someone who keeps your fingers and toes polished at all times, be sure to examine them on occasion and discuss any dramatic changes with a dermatologist. If you are looking to strengthen your nails, Dr. Rigby says you should first consider your diet. “It’s essential to eat an appropriate amount of protein and iron,” she shares. “Whether this is animal or plant based, protein is an essential component to the health of our hair, skin, and nails.”