SymptomSkin, hair & nails
Nail Ridges: What Vertical and Horizontal Ridges Mean
Nail ridges are raised lines or grooves on the nail surface. Vertical ridges, running from the cuticle to the tip, are very common and usually just a sign of aging or dryness. Horizontal ridges running side to side, called Beau's lines, are more significant: they show that nail growth was briefly interrupted, by a high fever, serious illness, chemotherapy, injury or a skin condition near the cuticle. A dark streak, a single ridge with a split or bleeding, or nail changes with other symptoms should be checked.
Also called: Ridged nails, vertical nail ridges, longitudinal ridging, horizontal nail ridges, Beau's lines, onychorrhexis
At a glance
- Vertical ridges
- Common, usually harmless, increase with age and dryness.
- Horizontal ridges (Beau's lines)
- A temporary pause in nail growth after illness, fever, chemotherapy or injury.
- Other ridge patterns
- Pitting and ridges in psoriasis; a central groove from habit picking; ridging with thinning in lichen planus.
- Red flags
- A dark stripe, a single ridge with splitting or bleeding, or nail changes across all nails with feeling unwell.
- Care
- Moisturize nails and cuticles, avoid harsh chemicals and picking, treat any underlying condition.
When to get help
See a doctor within a day or two
- A new dark brown or black stripe along a nail, especially if it widens, has blurred edges, or the color spreads to the skin around the nail
- A child with fever for 5 or more days and red eyes, rash, red lips or swollen hands and feet (possible Kawasaki disease; nail lines appear later)
Book a routine appointment
- Horizontal ridges on several nails without an obvious recent illness
- A single nail with a ridge or split that has a growth, lump, bleeding or pain beneath it
- Ridges with pitting, thickening or the nail lifting off the bed
- Nail changes with fatigue, pale skin or other symptoms
Usually safe to manage at home
- Fine vertical ridges on several nails in an adult, without other changes
- A horizontal line that appeared after a known illness or injury and is growing out
Vertical vs horizontal nail ridges
| Vertical ridges | Horizontal ridges (Beau's lines) | |
|---|---|---|
| Direction | Cuticle to tip | Side to side |
| How common | Very common | Less common |
| Usual cause | Aging, dryness, minor trauma | Interruption of nail growth |
| Seriousness | Usually harmless | Points to a past event; usually resolved by the time you notice |
| Grow out? | No, often persist | Yes, as the nail grows |
Vertical nail ridges
Fine vertical ridges (longitudinal ridging or onychorrhexis) become more noticeable with age, much like wrinkles in skin. Nail cell turnover becomes uneven and the nail loses moisture. Other contributors:
- frequent handwashing, cleaning products, nail polish remover and gel manicures
- dry indoor air
- eczema around the nails
- lichen planus, which causes ridging, thinning and sometimes scarring of the nails
- thyroid problems and poor circulation, occasionally
A deeper single ridge or groove on one nail has more specific causes:
- Habit tic deformity: repeated picking or pushing back of the cuticle, usually on the thumbs, creates a central channel with many small horizontal ridges like a washboard.
- Median nail dystrophy: a split down the middle, sometimes after isotretinoin.
- Something pressing on the nail matrix, such as a cyst, wart or, rarely, a tumor. A single ridge with a split, bleeding or a lump needs a dermatologist.
Horizontal nail ridges (Beau's lines)
The nail is made by the matrix under the cuticle. If the matrix stops working for a while, a groove forms across the nail. As the nail grows out, the groove moves toward the tip. Fingernails grow about 3 mm (1/8 inch) a month, so you can estimate when the event happened: a line 6 mm from the cuticle means about 2 months ago.
Causes:
- Severe illness or high fever: pneumonia, COVID-19, flu, measles, hand-foot-and-mouth disease
- Chemotherapy and some other medicines
- Heart attack, major surgery or severe stress
- Uncontrolled diabetes, zinc deficiency or severe malnutrition
- Kawasaki disease in children, with lines appearing weeks after the illness
- Local causes: injury to the nail, manicure damage, eczema or psoriasis around the nail fold, or a paronychia (infection of the nail fold)
Beau's lines on all nails point to a body-wide cause. A line on one nail usually means local trauma.
Other ridge-like nail changes
- Pitting: small dents, typical of psoriatic nails, eczema and alopecia areata.
- Muehrcke's lines: white paired bands that do not form a groove, seen with low protein in kidney or liver disease.
- Spoon nails (koilonychia): thin, concave nails with iron deficiency anemia.
- Fungal nail infection: thickened, yellow, crumbly nails rather than neat ridges.
Do nail ridges mean a vitamin deficiency?
Ordinary vertical ridges are not a reliable sign of a vitamin deficiency. Iron deficiency more typically causes brittle or spoon-shaped nails, and zinc or protein deficiency can cause Beau's lines. If you have other symptoms such as tiredness or pale skin, ask your doctor about blood tests rather than taking supplements blindly. Biotin supplements may help brittle nails in some people but can interfere with lab tests, including thyroid and heart tests.
When to see a doctor
See a dermatologist or primary care doctor if ridges come with discoloration, pitting, thickening, nail lifting, pain or swelling, if a single nail is affected with a split, or if Beau's lines appear without a known cause. A pigmented stripe needs prompt review to rule out nail melanoma.
The doctor will examine all nails, often with a dermatoscope, and may order blood tests or a nail clipping for fungus. A biopsy of the nail matrix is occasionally needed.
Caring for ridged nails
- Moisturize nails and cuticles daily with a thick cream or oil, especially after washing.
- Wear gloves for cleaning and washing dishes.
- Use acetone-free polish remover and limit gel and acrylic manicures.
- Do not pick, bite or push back the cuticles.
- Gently buff ridges with a fine buffer if you want them smoother; do not over-file, which thins the nail.
- A ridge-filling base coat can smooth the surface cosmetically.
Frequently asked questions
Are vertical ridges on nails normal?
Yes. Vertical ridges are very common and usually a normal part of aging, similar to wrinkles in skin. Dryness and frequent handwashing make them more noticeable. They need checking only if they come with color changes, splitting, pain or changes to the nail's shape.
What do horizontal ridges on fingernails mean?
Horizontal ridges, called Beau's lines, mean nail growth paused for a time. Common causes include a high fever, serious illness, chemotherapy, injury or skin inflammation near the cuticle. They grow out over several months. Lines on all nails without a known cause should be checked.
What vitamin deficiency causes nail ridges?
Vertical ridges are rarely caused by a vitamin deficiency. Zinc or protein deficiency can contribute to horizontal ridges, and iron deficiency causes brittle or spoon-shaped nails. If you have other symptoms, a blood test is better than guessing with supplements.
Can nail ridges be a sign of thyroid problems?
Sometimes. Thyroid disease can make nails brittle, ridged or slow-growing, but nail ridges alone are not a reliable sign. Look for other symptoms such as tiredness, weight change, hair thinning or feeling unusually cold or hot, and ask your doctor about testing.
How long do Beau's lines take to grow out?
Fingernails grow about 3 mm a month, so a horizontal ridge takes around 4 to 6 months to grow out completely. Toenails grow more slowly and can take 12 to 18 months.
Sources
This guide was written from current patient and clinical guidance, including:
- American Academy of Dermatology: 12 nail changes a dermatologist should examine
- American Osteopathic College of Dermatology: Beau's Lines
- Mayo Clinic: Fingernails - Do's and don'ts for healthy nails
- DermNet: Nail ridges and Beau lines
- American Family Physician: Nail Abnormalities - Clues to Systemic Disease