Brittle nails: causes, treatment and when to see a GP

There is rarely a single cause. The NHS says most nail problems are caused by injuries or biting your nails, staining your nails (for example by smoking or applying a lot of nail varnish), not regularly trimming your nails or cutting them at an angle, your hands often being in water or cleaning products, and a fungal nail infection.

Some changes are part of normal life. The NHS says it is normal for nails to become thicker or break more easily (brittle) as you get older, and to become harder, softer or more brittle during pregnancy, with nails expected to be healthier within 6 months of having a baby.

Repeated wetting can matter too. The British Association of Dermatologists (BAD) leaflet on chronic paronychia notes that excessive wetting of the hands, nail cosmetics and treatments, and irritants and allergens such as nail polish can damage the skin around the nail, and its leaflet on fungal nail infection says yeast infections often affect fingernails that have been damaged by excessive hand washing or wet work.

Sometimes. The NHS says nail problems can be a symptom of a more serious or long-term condition, such as psoriasis, iron deficiency anaemia, an underactive or overactive thyroid, diabetes, or heart, lung or liver disease. It also says some medicines can cause nail problems, so check the side effects of any medicine you take.

The NHS page on iron deficiency anaemia lists nail changes, such as spoon-shaped nails, among the symptoms, and its page on nail problems describes spoon-shaped nails that curve inwards (koilonychia) as a possible sign of iron deficiency anaemia. These are different from simple brittleness, and a blood test through your GP can check iron levels.

Do not start supplements on your own to treat brittle nails. If you suspect an underlying cause, ask a GP or pharmacist first.

The NHS gives practical advice that applies to brittle nails as well as other common nail problems. There is no medicine listed on its page for brittle nails themselves, so the focus is on protecting the nails and treating any cause that is found.

• Wear rubber gloves if your hands are often in water or you regularly use cleaning products.

• Clean your nails with a soft nailbrush.

• Apply hand cream to your nails and fingertips regularly.

• Trim your nails regularly; it may help to cut them after a shower or bath.

• Cut injured or loose nails back to where they are still attached, so they do not bend or catch on objects.

• Do not cut your nails down the edges; trim straight across the top to help avoid an ingrown toenail.

• Do not clean under your nails with sharp objects, and do not bite or pick your nails or the skin around them.

• Do not ignore fungal infections of the skin, such as athlete's foot.

The NHS says you may have a fungal nail infection if your nail is brittle, discoloured or thicker than usual. Fungal infections usually affect toenails, start at the edge of the nail, and can make it thick, white or yellow, brittle and crumbly. The nail may lift off and the skin around it become swollen and painful.

The NHS says a pharmacist can suggest an antifungal nail paint, which needs to be used for 6 to 12 months, and a GP can prescribe tablets if pharmacy treatments have not worked, after testing a nail sample. BAD adds that other nail problems, such as psoriasis, can look very similar to fungal nail infection, which is why a nail clipping is often sent to a laboratory to confirm the diagnosis. BAD also says toenail infections may take 12 to 18 months to clear and fingernails 9 to 12 months.

Not every brittle nail is infected, so avoid treating for fungus without a test if you can.

The NHS says to see a GP if the skin around your nails has become sore, red, swollen and warm (paronychia), which can be a sign of an infection or ingrown toenail. BAD describes chronic paronychia as inflammation of the skin around a nail lasting more than 6 weeks.

BAD says it can cause tenderness, swelling, pus-filled blisters and changes in nail shape, colour or texture (ridges) that may stay visible for many months after the paronychia has cleared as the nail slowly grows out. Its self-care advice is to keep hands as warm and dry as possible, wear gloves for tasks involving water, irritants and chemicals, avoid biting nails or pushing back cuticles, and avoid nail varnish until the condition has been treated.

The NHS suggests seeing a GP if a nail has changed shape, changed colour or fallen off and you do not know why, or if the skin around the nails has become sore, red, swollen and warm. See a podiatrist if your nails are too tough to cut or you cannot reach them.

The NHS says some GPs may refer you to a podiatrist, and that you might be able to refer yourself directly without seeing a GP in some areas. To find out, ask your GP surgery reception, check the surgery website or contact your integrated care board.

See a GP sooner if you have diabetes or a weakened immune system and develop a nail infection, because the NHS says foot problems can be more serious in these situations.

Most people manage brittle nails with self-care and, if needed, a conversation with a pharmacist. A GP can check for underlying causes, take a nail sample for fungal testing or arrange blood tests. Podiatry is available through the NHS in some areas, and some people choose to see a private podiatrist or dermatologist. The assessment and the advice on nail care are the same in either setting, and your GP should be told about anything that is found.