Nails

7 Signs Your Nails Are Telling You Something About Your Health

Nails reflect internal changes long before other symptoms appear. Here are seven specific signs to notice — and what they may indicate.

Nails grow slowly — roughly 3mm per month — which means they act as a kind of biological timeline. Changes in texture, colour, and shape often reflect what was happening inside the body weeks or even months earlier. Most nail changes are benign. Some are worth noting. A few are worth discussing with a GP.

This article is informational only and does not constitute medical advice. If you are concerned about any change in your nails, please consult a qualified healthcare professional.

White Spots

White spots — medically known as leukonychia — are among the most common nail findings, and one of the most misunderstood. The popular belief is that they signal calcium deficiency. In the vast majority of cases, they do not.

They are almost always caused by minor trauma to the nail matrix — the growth centre beneath the cuticle. Catching a nail on something, pressing too hard during a manicure, or even wearing tight shoes can all produce a white spot that appears weeks later as the nail grows out.

Occasionally, zinc deficiency can produce white spots, particularly if they appear across multiple nails simultaneously. This is worth mentioning to a GP if the pattern is consistent and persistent. A single white spot on one nail, however, is nearly always the result of a bump you have already forgotten.

Horizontal Ridges (Beau's Lines)

Horizontal ridges run across the nail from side to side, perpendicular to the direction of growth. These are called Beau's lines, named after the French physician who first described them.

They indicate that nail growth was temporarily disrupted. The nail matrix pauses growth during periods of significant physical stress — a serious illness, high fever, surgery, or severe nutritional disruption. The ridge marks the point where growth slowed or stopped before resuming.

Because nails grow at approximately 3mm per month, you can estimate when the disruption occurred by how far the ridge sits from the cuticle. Beau's lines appearing across all ten nails simultaneously suggest a systemic event. A single line on one nail is more likely the result of localised injury. If you notice these lines without a clear explanation, it is worth raising with your GP. Our article on nail ridges explains both horizontal and vertical ridging in detail.

Vertical Ridges

Vertical ridges run from the cuticle toward the tip of the nail. Unlike horizontal ridges, these are extremely common and, in most cases, entirely normal. They become more pronounced with age as cell turnover slows and the nail plate becomes drier.

If vertical ridges appear suddenly or worsen noticeably over a short period, it is worth paying attention. Iron deficiency anaemia and vitamin B12 deficiency can both contribute to more prominent vertical ridging, often alongside other symptoms such as fatigue or pallor. If the ridges are accompanied by other changes, a simple blood test can confirm or rule out nutritional factors.

The nail does not cause these changes — it records them. Treating the surface addresses the cosmetic result; addressing the root cause prevents further changes.

Spoon-Shaped Nails (Koilonychia)

Koilonychia describes a nail that has flattened and then curved inward — the nail plate becomes concave, like a small spoon, to the point where it could theoretically hold a drop of water.

This is a classic clinical sign of iron deficiency anaemia, particularly in its more advanced stages. It can also appear in conditions affecting iron metabolism. It is rarely caused by anything minor. If you notice this shape change in your nails, particularly across multiple fingers, a GP visit and blood test are appropriate rather than optional.

Yellow or Discoloured Nails

Yellow nails most commonly indicate a fungal infection of the nail plate (onychomycosis). Fungal infections also cause the nail to thicken, become brittle, and sometimes separate from the nail bed at the edges. They are treatable but require patience — antifungal treatments work slowly.

Less commonly, yellow discolouration is associated with psoriasis, which can affect nails even in the absence of skin symptoms. Rarely, persistent yellow nails across multiple digits are linked to thyroid dysfunction or chronic respiratory conditions, though these presentations are typically accompanied by other symptoms.

A single yellow nail is often fungal. If over-the-counter antifungal treatment makes no difference after several weeks, a GP or dermatologist can confirm the cause and advise on prescription options.

Pitting

Pitting appears as small, shallow dents on the surface of the nail plate. The nail looks as though it has been lightly pressed with a pin in a scattered pattern.

Pitting is strongly associated with psoriasis — it appears in the majority of people who have nail psoriasis, and sometimes presents before any skin symptoms. It is also associated with alopecia areata, an autoimmune condition affecting hair follicles.

If you notice new pitting across several nails and have no history of psoriasis, it is worth mentioning to a GP, particularly if you have noticed any changes in your scalp hair or skin.

Pale or White Nail Beds

The nail bed — the skin visible through the nail plate — is normally a healthy pink. Significant pallor or near-white nail beds can indicate low haemoglobin levels, which occurs in various forms of anaemia.

To assess, press the nail bed gently, release, and observe how quickly colour returns. Slow return and persistent pallor in a person who is also experiencing fatigue, dizziness, or shortness of breath warrants a GP consultation and blood count check.

Pale nail beds in isolation, particularly in cold weather or after pressing, are often circulatory and benign. Persistent pallor across multiple nails in combination with other symptoms is more significant. Understanding which nutrients most affect nail health can be a useful complement to any GP conversation about these patterns.

At Maison Lumia, we work with nails every day, and we notice these details. If something catches our eye during your appointment, we will mention it — not as a diagnosis, but as a prompt to pay attention. Your practitioner is a useful second pair of eyes, and your GP is always the right next step when something warrants a closer look.