Most of us don’t pay much attention to our fingernails unless one breaks.
But take a closer look.
Changes in your nails can sometimes offer clues about what’s happening elsewhere in your body. Most nail changes have harmless explanations, and no single nail symptom can diagnose a health problem.
Still, these seven changes are worth noticing—especially if they’re new or don’t go away.
1. Nails That Have Become Pale
Nails naturally vary in color, and they can become somewhat paler with age.
But noticeably pale nail beds can sometimes occur with anemia, including iron-deficiency anemia.
If pale nails appear along with unusual fatigue, weakness, shortness of breath or dizziness, it’s worth mentioning to your doctor.
A blood test—not the appearance of your nails—is the way to determine whether you’re actually anemic.
2. Spoon-Shaped Nails
Do your nails appear to curve upward around the edges, almost like a tiny spoon?
This condition is known as koilonychia.
It can sometimes be associated with iron deficiency, although there are other possible causes.
Rather than immediately taking iron, talk to your doctor. Too much supplemental iron can be harmful when you don’t actually need it.
3. Tiny Pits in the Nail Surface
Small dents that look as though someone pressed a pin into your nail are known as nail pitting.
They’re frequently associated with psoriasis, particularly in people who already have psoriasis elsewhere on the body.
Nail pitting can have other causes, too, so persistent changes deserve a closer look.
4. Nails That Become Thick and Yellow
A thick, yellow or crumbly toenail or fingernail is commonly associated with a fungal infection.
These infections become increasingly common with age and can be stubborn to treat.
But not every yellow nail is fungus. Nail polish, smoking, trauma and certain medical conditions can also change nail color.
A clinician can help determine the cause before you spend months treating the wrong problem.
5. A New Dark Line Under One Nail
Dark vertical streaks in nails can occur for harmless reasons, particularly in people with darker skin tones.
But a new or changing dark streak in a single nail deserves attention.
In rare cases, pigment underneath a nail can be a sign of melanoma.
Changes that widen, become irregular or extend onto the surrounding skin should be evaluated by a dermatologist.
6. Rounded, Bulging Fingertips
If the tips of the fingers gradually enlarge and the nails begin curving downward around them, this is called clubbing.
Clubbing can sometimes be associated with underlying lung, heart or other medical conditions.
It generally develops gradually and should be evaluated rather than self-diagnosed.
7. Horizontal Grooves Across Several Nails
Horizontal depressions running across a nail are sometimes called Beau’s lines.
They can appear when nail growth is temporarily interrupted by significant illness, injury, severe stress on the body or certain treatments.
Because fingernails grow slowly, the groove may become noticeable weeks after the event that caused it.
Your Nails Are Clues—Not a Diagnosis
The most important thing to look for isn’t whether your nails perfectly match a picture you saw online.
It’s change.
A nail you’ve had your entire life is very different from a dark streak that suddenly appeared last month.
Pay particular attention to changes that are new, worsening, painful or affecting several nails at once.
Your fingernails won’t tell you exactly what’s happening inside your body—but occasionally, they can tell you when it’s worth looking a little closer.
