Ridges in nails: what your nails are giving away

Most ridges in nails are normal ageing and mean nothing. The handful of nail changes that do mean something are specific enough that knowing which is which is worth more than any supplement.

The ridges that are normal

• Vertical ridges, running from the cuticle to the free edge, both hands, more visible with age, with no change in colour or thickness. These are the commonest worry and they are the least significant thing on this page. They are the nail equivalent of a wrinkle.
• They catch the light more when the nail is dry, which is why they look alarming after washing-up and disappear after oil.
• A few horizontal lines in a person who has had two fevers this year are also unremarkable, since the nail records whatever happened while it was growing.
• Nothing is being deficient in a nail with fine vertical ridges, and no amount of biotin, gelatin or calcium changes them.

The changes that are worth reading

• Horizontal grooves running right across the nail, sometimes with the nail peeling in layers, appearing on several nails at the same distance from the cuticle: Beau's lines. They mark a time when growth stopped, weeks earlier: a serious fever, surgery, chemotherapy, a bad infection, hand-foot-and-mouth disease, or zinc deficiency. The position on the nail dates the illness, which is genuinely useful.
• A spoon-shaped nail, hollowed so it holds a drop: koilonychia, and it points to iron deficiency, often before the blood count is abnormal.
• Small pits, as if the nail has been pricked with a needle, in a cluster: psoriasis, and it travels with the joint question. Also seen in eczema and alopecia areata.
• The nail lifting away from the bed, with a white and then yellow-green edge: onycholysis, from psoriasis, fungus, thyroid disease, or trauma and long fingernails.
• Thick, crumbly, discoloured nails that will not clip straight: fungal nail infection, which needs months of oral treatment with liver monitoring, and which creams do not fix.
• A single dark vertical band on one nail, widening, or with pigment spreading onto the surrounding skin: this needs a dermatologist, not a supplement. Subungual melanoma is rare and it presents exactly this way, most often on a thumb or a big toe in a person with darker skin.
• Thin dark red-brown lines running lengthwise under the nail plate, like splinters: from knocks and hard manual work usually, and rarely from infection of the heart lining when they come with fever and weight loss.
• Nails that are entirely white with a normal pink band at the edge, or half-white and half-brown: these accompany liver and kidney disease, and they are a blood-test conversation.
• Fingertips that have become broad and rounded, with the nail curving around them: clubbing, which reflects lung, heart, liver and bowel disease and needs the chest examined rather than the nail treated.
• Pale nails with a thin blue or dark rim, and nails that separate with pain and swelling at the cuticle: anaemia, and infection or inflammation at the nail fold.

What we ask

• Which nails, how many, and whether both hands are affected. Several nails at once points to something internal; one nail points to local trauma or infection.
• When it started, and what happened around then: a fever, a serious infection, an operation, a new medicine, a bad month.
• Diet, and whether there is a history of heavy periods, blood donation, vegetarianism without planning, or a gastrointestinal complaint.
• Skin and hair, since nail disease rarely travels alone: scalp, elbows, knees, nails of the toes, and hair loss.
• Medicines, including the ones that make nails fragile or pigmented.
• Habit: long nails, picking at the cuticle, gel and acrylic applications, aggressive filing, and the amount of water and detergent the hands are in.
• Family history of psoriasis, and whether anyone else has the same nails.

What we look at and what we test

• All twenty nails, the nail folds, and the free edge, plus the skin and scalp, plus the joints of the fingers.
• A scraping or clipping from a thickened nail sent for fungal testing, because months of treatment should not be started on appearance alone.
• Bloods chosen by the pattern: a full count, ferritin and iron studies, B12, vitamin D, thyroid function referred onward, sugar, liver and kidney function, and inflammatory markers.
• Clubbing, a dark band, or a change that does not fit any of these goes to a specialist with the photographs rather than being watched.

What actually helps

• Correcting what the bloods found. Iron, B12 and protein are the treatments for the nutritional group, and they are given in a proper dose for a proper time and then re-tested.
• Real protein at every meal, since the nail plate is keratin made from what is eaten, and a low-protein diet shows up in the nails and the hair.
• For fungal nails, the full oral course with the monitoring it requires, plus treating the feet and the shoes, because a nail that clears and then re-infects from the toe web has not failed treatment.
• For psoriatic nails, the specialist treatment for the disease rather than for the nail, and an answer to the joint question.
• For the ordinary vertical ridges: oil on the nail fold, gloves for washing-up, a file rather than a metal tool, and no aggressive buffing, which thins the plate and makes the ridges look worse in the long run.
• Leaving gel and acrylic alone for a few months if the nails have become thin, peeling or tender, since the removal process damages the surface far more than the product does.

The supplement question

• Biotin has a small evidence base for brittle nails and no evidence at all for ridges, and it interferes with thyroid and cardiac blood tests in a way that produces wrong results. If it is being taken, the laboratory has to be told.
• Gelatin, calcium and collagen do not change nail growth in anyone who is eating enough protein.
• Iron without a blood test is a poor idea: it causes constipation and black stools, it is unpleasant, and it is unnecessary if the ferritin is normal.
• A nail that is being treated with three supplements and no blood test is the most common situation we find on this page.

When to be seen without waiting

• A dark band on one nail, particularly a thumb or a big toe, that is widening, irregular, or with pigment on the skin around it.
• A painful, swollen, red nail fold with pus, or one that is not settling, especially in a diabetic.
• A nail that is destroyed, discharging, or lifting with pain, or a nail that has come off after an injury and is not regrowing normally.
• Nail changes with breathlessness, cough, chest disease, weight loss, or a swollen joint.
• Any nail change with a patch of numb skin, since leprosy affects the nerves and the diagnosis must not be delayed.

How we judge it

• Not by the month. A fingernail takes around four to six months to grow out and a toenail much longer, so a change that has been treated correctly looks better at the cuticle first and only later at the free edge.
• Where the new growth from the base is smooth, the treatment is working, and the damaged part simply has to be cut away over time.
• Whether the deficiency found has been corrected on a repeat blood test, which is the number that decides whether the nail will ever improve.
• Whether the one nail that should have been photographed and referred has been.