Nail abnormalities

Nail abnormalities include changes in the colour, shape, thickness, surface, or strength of a fingernail or toenail. A nail may also loosen from the skin beneath it or become painful around the edges.

Many nail changes come from minor injury, ageing, moisture, or repeated contact with chemicals. Fungal infections are another common cause, especially in toenails. Some changes are linked to skin conditions, medicines, or health problems elsewhere in the body.

Appearance alone usually cannot confirm the cause. A change affecting one nail may have a different explanation from a similar change affecting several nails.

A nail abnormality may cause no discomfort. When symptoms occur, you may notice tenderness, pressure, itching, or pain around or under the nail.

Changes may include:

• White, yellow, brown, green, blue, or black discolouration
• Ridges, grooves, pits, dents, or a rough surface
• Thick, brittle, splitting, or crumbly nails
• A nail lifting away from the skin underneath
• Curved, spoon-shaped, or unusually rounded nails
• Redness, swelling, warmth, or pus around the nail
• A new dark line running from the base toward the tip

Fine lengthwise ridges often become more noticeable with age. Small white marks commonly follow minor injuries and usually grow out with the nail.

Common causes include knocks, tight footwear, nail biting, manicures, and repeated pressure. Even a small injury near the nail base can produce a groove or white mark weeks later.

Frequent wet work, cleaning products, nail polish remover, and artificial nail products can dry or irritate nails. The nail may split, soften, or lift. The nearby skin can also become inflamed.

Fungal nail infection can make a nail thick, yellow or white, brittle, and crumbly. It most often affects toenails, but appearance alone cannot distinguish fungus from injury, psoriasis, or other conditions.

Inflammation around the nail is called paronychia. It may follow a torn cuticle, biting, picking, an ingrown nail, or repeated moisture. The skin can become red, swollen, and sore.

Less common causes include psoriasis, eczema, lichen planus, thyroid problems, iron deficiency, and side effects from some medicines. A major illness or physical stress can temporarily interrupt nail growth, leaving a groove across several nails.

Rounded fingertips with nails that curve downward are called clubbing. Spoon-shaped nails curve inward. These patterns can sometimes be associated with an underlying medical condition, but they do not identify a specific diagnosis by themselves.

A dark streak may come from normal pigmentation, injury, or bleeding under the nail. Less commonly, pigment can be caused by melanoma, a type of skin cancer.

Call emergency services if your nails or fingertips suddenly look blue or grey and you also have trouble breathing, chest pain, confusion, severe weakness, or fainting. The colour may reflect low oxygen rather than a nail problem.

Seek same-day medical care if redness or swelling around a nail is rapidly spreading, there is pus with fever, or the pain is severe. Prompt care is also appropriate after a deep cut, a badly crushed finger or toe, a partly torn-off nail, or bleeding that will not stop.

Book a routine appointment if:

• A change persists, spreads, worsens, or affects several nails
• A nail is painful, repeatedly lifts, or becomes thick and crumbly
• You develop unexplained clubbing or spoon-shaped nails
• A new dark band appears, widens, becomes irregular, or spreads onto nearby skin
• Nail inflammation keeps returning
• You have diabetes, poor circulation, or a weakened immune system and develop a nail or surrounding skin problem

A healthcare professional may ask when the change started, whether an injury occurred, and whether one or several nails are affected. They may ask about footwear, wet work, nail products, skin conditions, medicines, and other symptoms.

They will examine the nails, surrounding skin, and sometimes your hands and feet. Looking at the nail under magnification can help assess pigment or surface changes.

If fungus is possible, a nail clipping or scraping may be examined. Testing is useful because several conditions can resemble fungal infection. Blood tests may be considered when the pattern suggests iron deficiency, thyroid disease, or another health problem. A small nail or skin sample is occasionally needed to investigate an unusual growth or dark band.

Treatment depends on the cause. An injured nail may only need protection and time to grow out. Infection, inflammation, and underlying skin conditions may need specific treatment.

You can reduce further damage by keeping nails clean and cutting them straight across. Smooth rough edges gently rather than pulling or biting them. Do not cut or push back cuticles aggressively because they help seal out irritants and germs.

Wear well-fitting shoes and change damp socks. For frequent wet work, use protective gloves and dry your hands carefully afterward. Moisturising the nails and nearby skin can help with dryness and splitting.

Do not share nail clippers or files. Avoid covering a painful, infected, or unexplained discoloured nail with artificial nails.

Fungal treatment may be applied to the nail or taken by mouth, depending on the diagnosis and severity. Oral treatment requires medical assessment and is not suitable for everyone. A pocket of pus around a nail may need drainage; do not try to drain it yourself.

Nails grow slowly, so improvement may not be visible right away. A fingernail often takes about six months to replace itself. A toenail may take 12 to 18 months.

Damage or discolouration usually moves toward the tip as healthy nail grows from the base. If the nail growth area has been permanently injured, some change may remain.

Conditions such as psoriasis or recurring inflammation can improve and return. Follow-up may be needed if treatment is not working, the nail becomes more painful, or its appearance continues to change.

Do white spots mean I have a vitamin deficiency?

Usually not. Small white spots commonly follow minor knocks or manicure-related injury. Widespread or persistent changes deserve assessment rather than starting supplements without a confirmed deficiency.

Can nail polish cause abnormalities?

Polish can stain the nail surface, while removers and artificial nail products may cause dryness or irritation. A change that remains as the nail grows should not automatically be blamed on polish.

Should I treat a thick yellow nail as fungus?

Not without considering other causes. Injury, psoriasis, and ageing can look similar. Testing may be recommended before treatment, especially before oral antifungal medicine.

Will a damaged nail fall off?

It may loosen or shed after a significant injury. A new nail can often grow underneath, although replacement takes months. Seek care if there is severe pain, infection, or major damage.