Our nails can tell us a lot about our health. We might not always notice them, but changes in their appearance can be a sign that something’s going on beneath the surface. One common nail change is the appearance of vertical white lines. These lines can be a cause for concern, prompting a trip to the doctor to figure out what’s going on.
These vertical white lines on nails are medically known as leukonychia striata. They are white lines that run from the bottom of your nail near the cuticle, toward the tip of your nail, parallel to the lunula (the moon-shaped area at the base of the nail).
This article will explore some of the reasons why you might see vertical white lines on your nails. We’ll look at both harmless and potentially more serious causes and help you understand why getting a proper diagnosis and treatment plan is so important. When it comes to your health, it’s always best to be informed and proactive.
Basic nail anatomy and physiology
Before we dive into vertical white lines, let’s review basic nail anatomy.
- Nail plate: That’s the hard, visible part of your nail.
- Nail bed: This is the skin underneath the nail plate.
- Nail matrix: This is where the nail grows from. It’s located under the skin at the base of your nail.
- Cuticle: This is the skin that overlaps the base of your nail.
Your nails are made of keratin, the same protein that makes up your hair and skin. The nail matrix is responsible for nail growth. Cells in the matrix divide and push older cells forward, which then harden and flatten to form the nail plate. Fingernails grow about 3 mm per month, while toenails grow much slower, at about 1 mm per month.
Your nails can tell you a lot about your overall health. When your body is fighting an infection or dealing with a nutritional deficiency, your nails are often immediately affected.
Nail examination essentials
A thorough examination of your nails is essential. It’s not just about aesthetics; nail appearance can be a window into your overall health. In fact, doctors can diagnose systemic diseases just by looking at your nails. That’s why clinicians should always inspect your fingernails and toenails during routine checkups.
To do a proper nail examination, you must first remove any nail polish. Otherwise, the polish can mask any underlying nail abnormalities. If you notice any nail changes, be sure to document them. You can take a photograph and measure the nail to keep track of the changes.
What are vertical white lines on nails?
Vertical white lines on your nails are referred to as leukonychia striata by doctors and dermatologists.
Leukonychia (loo-kuh-NICK-ee-uh) is a medical term that refers to changes in the color of your nails. “Leuko-” means white, and “-nychia” refers to the nails. The changes can be spots, partial changes, or total changes.
Sometimes, leukonychia is nothing to worry about. But sometimes, it’s a sign of something else that may need medical attention.
There are two types of leukonychia: true and apparent.
True Leukonychia
True leukonychia originates in the nail matrix. That’s where your fingernails start to grow. True leukonychia involves changes to the nail plate itself. The changes are due to aberrant keratinization, meaning the nail isn’t forming the way it’s supposed to.
Common causes of true leukonychia striata are:
- Microtrauma to the nail matrix
- Onychomycosis (fungal infection)
- Inherited conditions like Hailey-Hailey disease and Darier disease
Fungal infections are the culprit in nearly 50% of true leukonychia cases.
Apparent Leukonychia
Apparent leukonychia originates in the nail bed. If you press on the nail, the white lines disappear. Apparent leukonychia arises from changes to the blood vessels in your nail bed.
Some kinds of apparent leukonychia are named for the doctor who first described them:
- Muehrcke lines: These are horizontal white bands that do not move as the nail grows. They are often associated with hypoalbuminemia (low levels of albumin in the blood) and other systemic illnesses.
- Half-and-Half Nails (Lindsay Nails): In this case, the proximal (closest to the hand) half of the nail is white, and the distal (farthest from the hand) half is red or brown. Half-and-half nails are associated with chronic renal failure.
- Terry Nails: With Terry nails, most of the nail bed appears white, except for a narrow band of pink or red at the distal edge. Terry nails are associated with cirrhosis, heart failure, and diabetes.
Longitudinal Melanonychia: Vertical Brown-Black Nail Lines
Now, let’s talk about something that looks a little scarier: longitudinal melanonychia. This presents as brown or black lines running from the base of your nail (the nail fold) all the way to the tip (the free edge). It’s like someone took a fine-tipped marker and drew a line right down your nail.
Longitudinal melanonychia doesn’t have just one cause, either. It can show up for a bunch of reasons, including:
- Trauma: Even a minor injury to the nail matrix (where your nail grows from) can cause it.
- Infection: Certain fungal or bacterial infections can trigger it.
- Medications: Some drugs can cause pigment changes in the nails.
- Endocrine disorders: Occasionally, hormonal imbalances can play a role.
- Racial melanonychia: This is a normal variation, especially common in people with darker skin tones. It’s basically extra pigment in the nail cells.
When to Suspect Melanoma (and See a Doctor ASAP!)
Here’s the really important part: Sometimes, longitudinal melanonychia can be a sign of melanoma, a type of skin cancer. It’s crucial to know when to get it checked out. One key sign is the “Hutchinson sign,” which is when the pigment from the line extends onto the skin around the base of the nail (the proximal nail fold). That’s a red flag.
Other things that should make you suspicious include:
- Band width: If the line is wider than 6mm (about a quarter of an inch), get it checked.
- New onset in adulthood: If you’ve never had it before and it suddenly appears as an adult, see a doctor.
- Rapid growth or change in color: Any sudden changes in the line’s size or color warrant a visit to the dermatologist.
Basically, if you’re at all worried about a dark line on your nail, don’t hesitate to get it looked at. It’s always better to be safe than sorry when it comes to potential melanoma.
Longitudinal erythronychia: Vertical red nail lines
Longitudinal erythronychia (LE) is a condition where you develop red lines that run from the base of your nail to the tip. It can affect just one nail (localized) or multiple nails (polydactylous).
If you have LE, your doctor will examine:
- How wide and how many red bands you have
- Whether you have any other nail changes
Glomus tumor
If you just have one red line on one nail, it could be a glomus tumor. These are benign (non-cancerous), but painful, tumors that grow under the nail.
Other causes of localized red nail lines
Other reasons you might see a red line on a single nail are:
- Trauma
- Warts
- Psoriasis
Red streaks on more than one nail
If you have LE on several nails, it could be a sign of:
- Lichen planus
- Darier disease
If you have red streaks on multiple nails, your doctor may want to do more testing to rule out underlying conditions.
Beau’s Lines
Beau’s lines are grooves that run across your nails, sort of like horizontal lines. You might also hear them called nail plate grooves.
These lines tell you that your nail growth was temporarily suppressed. Something caused your nails to slow down their growth, and that “something” could be a number of things, including stress or a systemic disease.
Common triggers for Beau’s lines include:
- Stress
- Systemic illnesses
- Medications
- Acute systemic stress
Since fingernails grow about 3 mm per month and completely renew themselves every four to six months, the position of the Beau’s lines can tell you when the event that triggered them happened. For example, if the line is halfway down your nail, the event likely happened two to three months ago.
Frequently Asked Questions
What vitamin deficiency causes white lines on nails?
While pinpointing one specific vitamin deficiency is tricky, white lines (especially horizontal ones, known as Muehrcke’s lines) can sometimes be linked to deficiencies in zinc or protein. However, it’s crucial to consult a doctor before self-treating, as other factors are usually involved.
What do vertical white lines on your nails mean?
Vertical white lines (or ridges) are usually harmless and often a sign of aging. They’re incredibly common! Sometimes, they can be more prominent due to dryness or minor trauma to the nail. Rarely, they could be associated with underlying conditions, so if you’re concerned, it’s always best to get checked out.
What does Merkel cell carcinoma look like?
Merkel cell carcinoma typically appears as a firm, painless nodule or bump, often red, pink, or skin-colored. It grows rapidly and is often found on sun-exposed areas like the head, neck, and limbs. It’s important to note that it does NOT usually appear on the nails. If you notice any suspicious skin changes, see a dermatologist promptly.
What autoimmune disease causes vertical ridges in fingernails?
Certain autoimmune diseases can sometimes affect the nails, leading to changes like pitting, thickening, or ridges. Lichen planus and psoriasis are two examples. However, vertical ridges are rarely the sole indicator of an autoimmune condition. Other symptoms would typically be present.
What vitamin causes vertical lines on nails?
No specific vitamin causes vertical lines on nails. As mentioned earlier, vertical ridges are generally a normal part of aging or can be due to minor injuries. Maintaining a balanced diet with sufficient vitamins and minerals is always a good idea for overall nail health, but it won’t necessarily eliminate existing vertical lines.
Conclusion
Vertical white lines on your nails can be caused by many things, from minor injuries to underlying health conditions. That’s why it’s important to know the difference between true leukonychia, which affects the nail bed itself, and apparent leukonychia, which is a change in the tissue under the nail, not unlike the discoloration you might see with green nails after false nails.
Your nails can offer clues about your overall health. So, while a few vertical white lines are usually nothing to worry about, it’s important to pay attention to changes in your nails. If you notice anything unusual, it’s always a good idea to talk to your doctor.
If your doctor suspects a more serious condition, they may refer you to a dermatologist. Dermatologists are experts in skin and nail conditions, and they may recommend a biopsy or other tests to get to the bottom of the issue.