What Do the Horizontal Lines on My Nails Mean?

Skin Care

What do the horizontal lines on my nails mean? It’s a fair question. Though western medicine arguably has the best diagnostic tools in the world, it is sometimes scoffed at when medicinal treatments treat only the symptoms, not the underlying causes. When dealing with diagnostic symptoms related to the nails, it can be interesting because widespread autoimmunity that causes asthma may be technically treated with an inhaler, but you can still see signs of inflammation in the nails using guidelines from eastern medicine.

Horizontal-Nail-Ridges

Horizontal nail lines run from side to side on the nail. When they form within or on the surface of the nail itself, these horizontal nail lines are known clinically as Beau’s lines. When they are deeper and more formed under the nail, they are called Mees’ lines. So here are what the horizontal lines on your nails may mean about your health and well-being:

Previous injury to your nail bed

“That’s impossible,” I know you’re thinking. I have horizontal lines on my nails now; if I had hit or crushed my nails off of something, surely I would remember.

But not so fast. Nails grow at the rate of just one-eighth of an inch per month. This means that an injury to your nail bed won’t show up for months, until the nail fully grows out. You may not even remember months-old minor events that traumatized the nail bed enough to create the horizontal ridges.

To avoid this in the future, be very careful with your hands. Though we all know cutting cuticles is a bad idea, it’s also a bad idea to push back your cuticles too harshly. In persons with soft nails, this can damage the nail bed with ridges that won’t show for months.

Nail Anatomy Diagram Cuticle Ridges

Underlying health conditions

It may sound scary, but most of the conditions associated with horizontal lines on your nails are conditions you would already be aware that you have.

According to Dr. Audrey Kunin, M.D., “Sudden illness (like a heart attack), malnutrition, and even the pain and stress of carpal tunnel syndrome can stop nail growth. When the nail starts growing out, it can result in horizontal lines.”

Arsenic poisoning, Renal failure, or Chemotherapy

Arsenic and thallium poisoning, renal therapy, and chemotherapy may also cause horizontal lines across the nail (Penn State Hershey School of Medicine). However, unlike trauma or malnutrition, these issues will form deeper Mees’ lines within the nails (photo), as opposed to the lighter surface lines that are Beau’s lines.

It is advisable if you think you have Mees’ lines to see a physician immediately, especially if you have other symptoms of heavy metal poisoning.

Bottom Line

My nervous habit is that I tend to pick my cuticles. Gross, I know, but it’s true. As a result, I used to always have horizontal lines on my nails until I started getting manicures ever 2-3 weeks. I always knew mine were from microtrauma, as it’s called in the derm world, but knowing their underlying cause made me feel better!

If you’re interested in knowing what the vertical lines on your nails mean, please visit our post!

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