Nail ridges are raised lines or grooves on the surface of the nail. Almost everyone has some. The direction of the ridges is what matters. Lines that run from the cuticle to the tip are usually harmless. Lines or dents that run from side to side tell a different story.
Vertical ridges
Vertical, or lengthwise, ridges run from the base of the nail to the tip.
- They are very common and tend to become more noticeable with age, in the same way that skin develops fine lines.
- They are usually even across several nails.
- They are often more visible when nails are dry.
Fine vertical ridges on their own are generally considered a normal variation and need no treatment.
When vertical ridges need attention
- A single dark brown or black stripe running the length of a nail should always be shown to a doctor or dermatologist promptly. It is often harmless, especially in people with darker skin, but it can be a sign of melanoma under the nail.
- A single deep groove or split in one nail can come from a growth near the nail root or from repeated injury.
- Ridges with brittleness, splitting and color change may be linked to a skin condition or another health problem.
Horizontal ridges
Horizontal ridges or grooves run across the nail. Deep ones are known as Beau's lines. They form when nail growth slows or stops for a time, and they move towards the tip as the nail grows.
Possible causes include:
- An illness with a high fever.
- An injury to the nail or the finger.
- Major surgery or severe physical stress.
- Some medical treatments, including chemotherapy.
- Poorly controlled long-term conditions.
- Severe nutritional shortage.
Because fingernails grow about three millimeters a month, the position of a groove tells you roughly when the interruption happened. A single episode needs no treatment and grows out. Repeated or unexplained horizontal ridges are worth discussing with a doctor.
Other surface changes
| What you see | What it may be |
|---|---|
| Small pits, like pinpricks | Often linked to psoriasis or eczema |
| A row of horizontal ridges down the center of the thumbnail | Often caused by a habit of rubbing or picking at the cuticle |
| White spots | Usually minor knocks to the nail root; they grow out |
| Rough, sandpaper-like nails | Can occur with some skin conditions |
| Spoon-shaped nails that curve upward | Sometimes linked to iron deficiency |
Nail Discoloration: Causes and When to Get Help explains changes in nail color.
Caring for ridged nails
- Moisturize. Rub cream or oil into the nails and cuticles daily. Ridges look deeper when nails are dry. See Cuticle Care: How to Keep Your Routine Gentle.
- Buff very gently, if at all. A few strokes with a fine buffer, no more than once a month, can soften ridges. Buffing them flat thins the nail, and ridged nails are often thin already. See Nail Files and Buffers: How to Choose the Right Grit.
- Use a ridge-filling base coat. It evens the surface under polish without removing nail.
- Protect your nails from water and detergents with gloves.
- Leave your cuticles alone. Pushing hard or picking at the base of the nail can cause ridges and dents.
What does not help
- Trying to file ridges away.
- Taking supplements without a diagnosed deficiency.
- Harsh nail hardeners, which can make dry, ridged nails more brittle.
When to see a doctor
- A new dark stripe, especially on one nail, or a stripe that is widening or changing.
- Horizontal grooves on several nails without an obvious cause.
- Ridges with pain, swelling, bleeding or a nail that is lifting.
- Pitting, thickening or crumbling.
- A change in one nail that does not grow out.
Photographing your nails once a month helps you and your doctor to see whether a change is moving out with growth. Nail Growth: What Affects It and How to Track It explains how to track nail growth. For general fragility, see Brittle Nails: Causes and Everyday Care Tips.
Related on ArniSun
- Nail Discoloration: Causes and When to Get Help
- Brittle Nails: Causes and Everyday Care Tips
- Nail Growth: What Affects It and How to Track It
- Nail Files and Buffers: How to Choose the Right Grit
- Cuticle Care: How to Keep Your Routine Gentle
Sources and further reading
Frequently asked questions
Are vertical ridges on nails a sign of a vitamin deficiency?
In most people they are a normal change that becomes more visible with age. A deficiency is an uncommon cause.
Do nail ridges go away?
Horizontal ridges from a single illness or injury grow out with the nail. Age-related vertical ridges tend to stay, but moisturizing makes them less noticeable.
Is it safe to buff out nail ridges?
Light, occasional buffing is fine. Buffing until the nail is flat removes too much of the nail plate and can lead to splitting.