Beau’s Lines

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Beau’s lines are horizontal indentations or ridges across the nail. They can develop on the fingernails and toenails and are caused by illness, injury, or infection. 

This article discusses the symptoms, causes, and treatment options for Beau’s lines.

nail indentations

PORNCHAI SODA / Getty Images

Symptoms of Beau’s Lines

The main symptom of Beau’s lines is the ridge that appears in the nail. The nail may also become discolored and appear yellow, like the color changes that occur in fungal infections. Other symptoms can develop depending on the cause. Since there are many causes, the symptoms will vary drastically.

Causes of Beau’s Lines

The exact cause of Beau’s lines isn’t well understood, but it develops when the nail growth from underneath the cuticle is interrupted. However, many diseases and infections can cause the nail to stop growing as it should, leading to Beau’s lines. Injuries and environmental factors also play a role in developing indentations in the nails. They are almost always caused by these outside stressors.

Some possible conditions and infections that cause the ridges to develop in the nails include:

Injuries can also play a role in the development of Beau’s lines, including:

  • Picking at the nails and cuticles repeatedly
  • Manicures or pedicures
  • Temporary reduction in blood flow due to trauma of the hand, wrist, or elbow
  • Nerve injuries that occur after fractures or carpal tunnel syndrome
  • Being in a cast or splint for a broken finger, hand, or wrist 
  • Major surgeries

Environmental and lifestyle factors can also lead to Beau’s lines, such as:

  • Psychological stress
  • Exposure to extreme cold temperatures
  • Malnutrition or nutrient deficiencies

Should You Worry About Beau’s Lines?

Noticing Beau’s lines can be concerning, especially considering how many possible causes there are for their appearance. It’s important not to jump to the worst-case scenario. The most common cause is tied to medication use.

What Medications Can Cause Beau’s Lines?

Several medications have been tied to Beau's lines, especially chemotherapy drugs. When you undergo chemo treatment, you will likely notice Beau's lines on your fingernails and toenails. The lines will also develop relatively quickly after treatment begins, such as within two to three weeks of starting chemotherapy.

Chemotherapy drugs cause Beau's lines by affecting the cells with a high turnover rate, such as those below the cuticle, where nails start growing (nail matrix). The cells reproduce slower, thus, slowing down the growth of the nail and causing the ridges.

What Other Drugs Cause Beau’s Lines?

While chemotherapy is the most likely drug to cause the ridges, other medications have been shown to initiate Beau’s lines, including:

  • Retinoids
  • Radiation therapy
  • Carbamazepine (used to control seizures)
  • Cloxacillin (an antibiotic)
  • Dapsone (used to treat skin disorders)
  • Itraconazole (used to treat fungal infections)

How to Treat Beau’s Lines

There is no one treatment for Beau’s lines, and therapy revolves around treating the cause, so treatment will depend on the underlying cause.

Once treatment for the underlying cause has commenced, Beau’s lines typically clear up within three to six months, which is generally how long it takes for the nail to regrow so the ridge can be cut off entirely. If caused by chemotherapy, it will take the same amount of time once chemotherapy has been completed.

At-Home Management of Beau’s Lines

While treatment for the health disorder is underway, you can try to keep your nails healthy and reduce the appearance of the ridges by:

  • Keeping your nails short
  • Avoiding any injury to the nails affected
  • Painting your nails using a gel polish to cover the ridges while the nail grows out

Are There Tests to Diagnose the Cause of Beau’s Lines?

Diagnosing Beau’s lines is simple because it can be done through physical examination. That said, diagnosing the cause is more complicated and needs to be done before any treatment can begin. The tests used to diagnose what is causing Beau’s lines will depend entirely on other symptoms you are experiencing and your health history and current state of health.

When to See a Healthcare Provider

See your medical provider if you notice any horizontal ridges in your nails. Because there are so many causes, some serious and some minor, it’s essential to rule out severe health conditions that could be causing the ridges to develop.


Beau's lines are horizontal dents in the nails. They can be caused by diseases, injuries, or infections. Because there are many causes, it can be hard to determine the treatment options until a diagnosis is made. If you notice the indentations in your nails and are not undergoing chemotherapy, speak to your healthcare provider to determine the cause and your treatment options.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Lee DK, Lipner SR. Optimal diagnosis and management of common nail disorders. Ann Med. 2022 Dec;54(1):694-712. doi:10.1080/07853890.2022.2044511

  2. Singal A, Arora R. Nail as a window of systemic diseases. Indian Dermatol Online J. 2015 Mar-Apr;6(2):67-74. doi:10.4103/2229-5178.153002

  3. Braswell MA, Daniel CR 3rd, Brodell RT. Beau lines, onychomadesis, and retronychia: A unifying hypothesis. J Am Acad Dermatol. 2015 Nov;73(5):849-55. doi:10.1016/j.jaad.2015.08.003

  4. MedlinePlus. Nail abnormalities.

By Angelica Bottaro
Angelica Bottaro is a professional freelance writer with over 5 years of experience. She has been educated in both psychology and journalism, and her dual education has given her the research and writing skills needed to deliver sound and engaging content in the health space.