Toenail Lines Explained: Know the Signs, Protect Your Health
What Are Horizontal Lines on Toenails? (Dark, White, Red or Black Lines)
Do you have horizontal lines on your toenails? We go over the treatment & meaning of black horizontal lines, white horizontal lines and more!
Toenail Pain (Toenail Fungus, Ingrown Toenails, Discolored Toenails)
Nail Problems
- Toenails Fungus Treatment
- Ingrown Toenail Treatment
- Impacted Toenail Treatment
- Onychocryptosis
- Bruised Toenail or Hematoma
- Discolored Toenails from Nail Polish
- Toenail Falling Off from Fungus
- Toenail or Toe Cancer
- Why is My Toenail Falling Off
- Why is My Toenail Falling Off
- Peeling Toenails
- Peeling Toenails
- Horizontal Lines on Toenails
- Horizontal Ridges on Toenail
Discoloration
Understanding Horizontal Lines on Toenails: What You Need to Know
Horizontal lines on toenails—also known as Beau’s lines—can be caused by a variety of factors, including illness, trauma, or underlying medical conditions such as psoriasis or diabetes. These lines may appear as ridges, grooves, or discoloration and are often a sign that something interrupted the nail’s normal growth. While they can sometimes be harmless, it’s important to consult a podiatrist to determine the exact cause and receive proper care. Early diagnosis can prevent more serious health concerns and ensure your nails return to full health.

Horizontal lines on toenails causes:
- If you notice a horizontal lines across your toenail? Don’t worry this is not a reason to panic.
- This is something called a Beau’s line. Beau’s lines are horizontal grooves in your toenails.
- These are depressions in your toenail that look like a big dent from side to side.
- This should not be confused with the vertical line as this could mean different things.
- Beau’s lines can occur on both your toenails and her fingernails.
- A person could have several Beau’s lines or horizontal lines along their toenails.
- The are almost always caused by an injury or repeated damage to the toenails or fingernails.
- This interrupts the growth of the toenail or fingernail for a short period of time.
Common causes of horizontal lines on the toenails include:
- Dropping something heavy on to the toenail.
- Jamming the toenail against the front of your shoe or bumping it against something.
- A period of heavy walking or standing.
- A period of heavy running and damage to the toenails.
- You could also get these horizontal lines from cold damage to your toes, which would stop the toenails from groin for a short period of time.

Rare but serious causes of horizontal lines on toenails include:
- There are more serious causes of Beau’s line or horizontal lines on the toenails and fingernails.
- Studies do show that nail diseases can frequently be associated with poor nutrition and systemic diseases.
- These more serious causes would indicate an issue with your body being able to grow tissues were toenail.
The more serious causes include:
- Malnutrition.
- Vitamin deficiency.
- Mineral deficiency.
- Zinc deficiency.
- Diabetes with an uncontrolled blood sugar period.
- Peripheral arterial disease secondary to smoking.
- Chemotherapy secondary to cancer.
- A serious illness like pneumonia.
- Chemotherapy or radiation.
What else can horizontal lines on the toenails mean?
- The American Academy of dermatology states “nails often reflect her general state of health.
- Changes in the nail such as discoloration or thickening can signal health problems or changes.”
What seasons are horizontal lines on the toenails most common?
- Study showed that the toenails actually grow slower in the winter than they do the summer.
- This could very easily because horizontal line or a bows line to develop.


The most common cause of horizontal lines on the toenails are called Beau’s lines. This can be caused by trauma or damage to the toenail.

A horizontal black line on the toenail or a horizontal red line on the root of the toenail or a cuticle can be trauma or toenail damage. It is usually not at bad as in this picture.
How long does horizontal lines on toenails take to grow out video:
- This video goes over how long it takes for a fingernail or a toenail to grow back after trauma or damage.
- The most common cause of a horizontal line (black, red, dark or white) is trauma to the toenail and will be corrected when a new nail replaces the damage.
7 Shocking Reasons You Have Horizontal Lines on Toenails
Horizontal lines on toenails—often called Beau’s lines—can be more than just a cosmetic concern. These grooves or indentations may be your body’s way of signaling an underlying issue. Here are seven surprising reasons they may appear:
1. Major Illness or Fever
High fevers from illnesses like the flu, COVID-19, or pneumonia can disrupt nail growth, leaving horizontal indentations once the nail continues to grow.
2. Trauma or Injury to the Nail Bed
Stubbing your toe or dropping something on it might not break the nail but can shock the nail matrix and temporarily pause growth—leading to visible lines later.
3. Nutritional Deficiencies
Lack of key nutrients like zinc, protein, or iron can impact nail health, slowing down cell production and creating ridges or lines across your toenails.
4. Psoriasis or Eczema
These chronic skin conditions can affect the nail matrix, resulting in ridges, pitting, or discoloration, including horizontal lines.
5. Chemotherapy or Radiation Therapy
Cancer treatments can temporarily stop nail growth, leading to the development of Beau’s lines as a side effect.
6. Uncontrolled Diabetes
Poor circulation and nerve function from unmanaged diabetes may affect nail health, and horizontal lines could be an early warning sign.
7. Stress or Shock to the System
Severe physical or emotional stress—like surgery, extreme anxiety, or a sudden life event—can disrupt nail formation for weeks, eventually revealing itself as visible lines.
Grow back your damaged toenail video summary:
How long does it take for a toe nail to grow back after falling off?
- It can take a long TIME, but we show you what makes your nail grow back faster!
- A toenail can can grow 1mm or less or not at all if not treated properly.
- There are 5 things that you can do to make your toenail grow back faster if you fall the tips we go over!
- If your toe nail fell off: We go over supplements, how to treat your toenail that fell off. If you want to grow long nails faster!
- Check our top 5 tips for making your nail grow fast!
White Horizontal Lines on Toenails Picture Gallery
Look:
- These photos are of dehydrated superficial nail keratin granulations vs. other toenail conditions.
- Keratin granulations are white chalky appearing dehydration.
- It is possible that some toenail fungus could be mixed in with the keratin granulations.
- It is also possible to have superficial white onychomycosis.
So click on the photos for gallery mode & description!
Frequently Asked Questions
- The most common cause of white horizontal lines of the toenails is something called Beau’s lines.
- This is most commonly caused by trauma or damage to the toenail.
- We usually see bumping, rubbing or jamming that temporarily stops the toenail from growing.
- This can cause an indentation or pitting in the toenail.
- Even though there is a chance that a black horizontal line could be a dangerous cancer called a melanoma, this is extremely unlikely.
- These lines tend to look like black vertical lines.
- The most common line associated with toenail cancer or melanoma is called Hutchinson sign.
- This is a vertical line that is over 3 mm in thickness.
If this is toenail cancer, the line could extend past the toenail into the skin. - If this was cancer, then the damage is actually underneath the toenail, not on the toenail.
- The most common cause of a horizontal black line on the toenail is due to trauma associated with bleeding.
- The dry blood becomes a black ridge or black line and takes many months to grow out.
- The most common cause of horizontal lines on the toenails means that there has been some type of trauma or damage this can cause white line.
- This is also known as a Beau’s line and is associated with fingernail and toenail trauma.
- Since the big toenail is usually the biggest and the longus toe for most people, most of the horizontal lines will usually appear on the big toe.
- In some people who have a second toe longer than the big toe, this horizontal white line is more likely to appear on the second toe.
- We usually find that nail damage happens most commonly on the big toe or the second toe, as these are usually the longus toes.
- It is also common to develop a white horizontal line on the fifth toe if the person has a foot that twists out or undergoes overpronation.
- If you have a horizontal black line on the toenail cuticle, this is usually an impacted toenail.
- We usually see this on the longest toenail when it is impacted back into the nail root.
- This can cause bleeding underneath the root of the toenail.
- If you have an impacted toenail and it is loosened, it may need to be removed.
- Especially if there is a blister or blood that has developed underneath this toenail.
- The most common cause of her red horizontal line on the toenail is trauma or damage to the toenail.
- This is a little bit more significant than a white toenail horizontal line, as there is a small amount of blood involved underneath this.
- If blood develops underneath the toenail, it usually means that when the toenail jammed it broke or cracked.
- Usually this is not anything dangerous or problems to worry about.
- If you are concerned go see a podiatrist for it diagnosis.
- Horizontal brown line could be either dried blood from a trauma or a minor impact, or it could be toenail fungus developing underneath that impacted site.
- Both are very common and both are unlikely to be toenail cancer.
- If the toenail is truly brown than this is more likely to be a yeast or a toenail fungus underneath the toenail.
- Click on her length for toenail fungus treatment to gait your brown toenail line better.
- Usually these lines are not due to something systemic.
- The feet are more likely to undergo trauma than the fingernails, especially if you are on your feet walking or running.
- This is most common in people take shoes are too much pressure on her toes that can develop problems to their toenails.
- Horizontal purple line on the toenail could usually discoloration of bright red blood flow that is starting to turn black.
- This could be combined with the lucency of the nail.
- It is unlikely that a fungus or a bacteria is truly going to look purple.
- A purple line is also rare for it to be toenail cancer.
- But if there is a concerning purple line that does not seem normal, always check with your podiatrist.
- A purple line could also mean a venous problem or poor blood flow to the nail bed such as a condition called cyanosis.
- If you do see purple underneath the toenail, check with your podiatrist as there may be a blood flow problem or venous stasis problem.
- This could be a condition known as a telangiectasia. This means that there is varicose veins in the region.