Thin Black Line on Nails, Vitamin Deficiency, Light Brown Line, Heart Problems, Melanoma, Thin Dark Lines on Nails, How to Get Rid

An overview of the thin black line, vitamin deficiency, light brown line, heart problems, melanoma, thin dark lines on nails and how to get rid

Thin black line on nail

A splinter hemorrhage is, simply, bleeding that is under the nail. The discoloration that emanates from the blood runs in direction that the nail grows, not horizontally, thus creating the appearance of a splinter that is under the nail. Even the color — which is a dark reddish-brown color — appears like the color of a wooden splinter.

Dark lines on nails

Dark lines on nails

The most common cause of the splinter hemorrhage is usually trauma to capillaries that are under the nail. The little capillaries usually burst or even break and clot, thus leaving a thin, dark line being under the nail.

Normally when you talk of trauma to a nail, you can immediately think of some kind of blunt-force trauma, like the one from hitting the nail using a hammer. However, the trauma which leads to a splinter hemorrhage might not hurt at all.

When a client comes to see the doctor with a splinter hemorrhage, a tech’s first response is supposed to be assisting of the client recall the event of trauma. Explain that the hemorrhage is likely that the result of bleeding and also clotting from tiny capillaries which run under the nails.

No treatment is required; the discoloration will grow out with a nail. There’s no given reason to be concerned if a patient doesn’t remember the exact event which brought about the said trauma. Most of the people won’t know what brought on the slight bruise.

Even though the trauma is the common cause of a splinter hemorrhage, it’s not usually the only cause. Splinter hemorrhages might also be brought on by fungal infections or even from psoriasis, though in both of the cases, there might be other symptoms that are beyond the appearance of hemorrhage.

Black line on fingernail vitamin deficiency

Dark lines on nails can be of diagnostic significance for many health problems. Below are some of the causes:

  • Black lines that are underneath the nails might develop due to trauma to finger nail. It is also very much similar to a bruise.
  • When a wood splinter or even the tiny lead of a pencil gets lodged under the nail, it can also appear as a black line.
  • Heart disease: splinter hemorrhages that are under the nail might also develop in late stage of the endocarditis. It is also a rare heart inflammatory disorder that develops as an underlying heart disease.
  • Vasculitis is an allergy related condition which can lead to dark lines under the skin.
  • Scurvy: this is a disease which emanates from deficiency of the vitamin C. In this particular disease the capillaries are very much fragile. Small amount of blood might leak from vessels that are under the nail and then occupy the place that is between the ridges. At the start, they are red lines but later on these lines become dark.
  • Black lines under nail are also an indicative of cirrhosis of liver.

Light brown line on fingernail

Melanonychia is characterized by the brown to black discoloration of the finger or even the toe nail. Longitudinal melanonychia usually describes a pigmented band and is also because of the melanin within the nail plate.

Dark lines on nails

Dark lines on nails

Longitudinal melanonychia is most often benign and usually arises from a pigmented melanocytic naevus or a lentigo. But, a band of brown pigment that is in a single nail should be examined and then investigated with a lot of caution, as melanonychia might also be the presenting sign of melanoma of the nail.

The nail is a hard and also translucent structure which is not normally pigmented and is made of the skin protein known as the keratin.

Pigmentation emanates from deposition of the melanin by pigment cells, or even the melanocytes. These usually lie dormant in nail matrix where nail originates.

As the melanin is deposited in the keratinocytic cells of growing nail, then a longitudinal streak will arise. This is known as the longitudinal melanonychia.

This deposition of the melanin might emanate from 2 broad processes which are; melanocytic activation or melanocytic hyperplasia.

Melanocytic activation

Melanocytic activation is an increase in production as well as the deposition of melanin into nail cells, without an increase in number of melanocytes. There are several causes.

Dark lines on nails

Dark lines on nails


  • Racial variation
  • Pregnancy


  • Nail biting
  • Friction: foot deformity
  • Carpal tunnel syndrome

Inflammatory skin disease

  • Psoriasis
  • Amyloidosis
  • Onychomycosis

What does a black line on toenail mean?

Repetitive Trauma

The common culprit for dark lines on nails, repetitive trauma can be due to running, or even from wearing any ill-fitting footwear. If a black nail crops up shortly after a workout in too-tight shoes, this can likely be the cause.

Repetitive trauma usually ranges from mild, to severe, as explained by Dr. Jacqueline Sutera, D.P.M. and also spokesperson for American Podiatric Medical Association. In the very mild cases, no treatment is required and the black nail will simply grow out.

Subungual Hematoma

Dropping a heavy object onto your foot might also burst the blood vessels that are under your nail bed and lead to blood to pool underneath. This type of blackened nail—clinically known as the subungual hematoma—is especially easy to identify, as it can appear immediately after an incident.

The buildup of blood usually causes a painful throbbing sensation which might be addressed by pricking of the tiny needle through the nail draining out the blood.

Dark lines on nails

Dark lines on nails

This procedure can also get rid of both the pressure as well as the dark color under the nail—and should then be done by your doctor, as at-home attempts are normally unsanitary and more excruciating than in-office care.

Dark lines on nails heart problems

Dark lines on nails normally emanate from splinter hemorrhages that is, bleeding under nails.

Splinter hemorrhages, which happen due to the blood vessel swelling or even the capillary damage, might then signal heart disease or even other heart conditions.

Heart Disease and Splinter Hemorrhages

Splinter hemorrhages usually appear in later stages of endocarditis, which is a rare heart valve infection that is prevalent in those people that have underlying heart disease which leads to inflammation of heart’s inner lining.

Another condition, vasculitis, might also lead to these dark lines on nails through an extreme allergic reaction which usually damages skin blood vessels.

Endocarditis and Vasculitis

Endocarditis results from the germs which enter through several other areas of the body, like the mouth and then infect the heart. This very rare condition emerges often in people who have existing heart disease and undergo heart or even dental surgeries.

People who are suffering from vasculitis normally develop painful skin lesions, like sores, blisters or even the hives in several areas of the body.

Other Causes

If a heart condition exists in the patient, other serious symptoms can also appear that leads to concern and likely lead to health monitoring before the splinter hemorrhages materialize.

The National Institutes of Health has shown that physical trauma to nail and the drug use through injections can also lead to the splinter hemorrhages.

Black line on nail melanoma

Dark lines on nails can be very serious than you can think. That’s the warning which one nail technician who comes from England gave her client after the client complained a lot of a black vertical line that was on her thumbnail.

Nail melanoma—officially known as the subungual melanoma if under the nail, or even the periungual melanoma if it’s around the nail, but potentially very deadly.

It makes up less than 3 percent of all the melanoma cases among the white people, but up to 38 percent of all the melanoma cases in the darker-skinned people, and about half of all the melanoma cases in those of Asian descent, according to a study in Dermatologic Surgery.

Dark lines on nails

Dark lines on nails

One reason that makes so serious is due to the fact that patients often don’t receive an accurate diagnosis immediately. In fact, according to study, the average delay of diagnosis for the subungual melanoma patients was about two and a half years.

That’s not because of the fact that people don’t notice dark mark—it’s due to the fact that they usually attribute it to something else.

Faint black line on nail

We have all been taught that any changes that are in a freckle or mole, with regard to color or shape, should be checked out with your doctor as soon as possible.  A dermatologist can tell whether the changes are suspicious looking, and if they need a biopsy.

Waiting to have the changes checked by a professional, leaves you open to the possibility of a skin cancer being undetected and thus potentially life-threatening.

Most of the people are unaware of the warning signs that are associated with cancerous tissue that is under the fingernails.

Melanomas in fingernail area is common amongst African Americans, but is also possible in every demographic of population.

How to get rid of dark lines on nails

But what if the dark lines on nails are not an indication of any serious health problems? Well, if that is the case, you might then easily do away with those black lines. Don’t conceal it using nail polish;

  1. Change your diet

If the appearance of dark lines on nails is because of the vitamin deficiency, the best thing that you might do to get rid of dark lines on nails is through eating a balanced and healthy diet.

It is usually recommended that you eat a lot of the foods that have high amounts of vitamin that you are deficient with.

With that in mind, you should ensure that you eat more of healthy as well as nutrient-rich foods such as leafy greens, bell peppers, fruits and fishes. Also, you can also take supplements such as zinc, vitamin C, and B as the inadequacy of any of them can lead to discolored nails.

  1. Get rid of the foreign body under your nails

Before you do that, make sure that you disinfect both your hands as well as the nails. Using a tweezer or any other nail tools, slowly pull the object out. Once you have already gotten rid of it, wash your hands. If there is any bleeding, then apply a bandage to your finger.

In the event that the foreign object is lodged deep in your nails, it is usually recommended that you let a doctor get rid of it.

  1. Let it be

In the case that the line is brought about by nail injury or even the trauma, the best thing to be done is just to let it be. The line is a blood clot, and many a times, it will disappear on its own even if you do not do anything about it.

  1. Seek help from a doctor

If you think that the dark lines on nails signify a serious condition, then you should visit a doctor immediately. In this way, your doctor might perform tests to determine if there’s something which is wrong and what it is.

When you visit the doctor early, you can be able to address the problem immediately and prevent it from getting worse.


The dark lines on nails might then imply nothing, or it might also indicate a serious health problem. Due to this, it is better that you seek the advice of a medical practitioner so that you can monitor your health as well as address any serious health problems which your nails are indicating.

But if the cause of dark lines on nails is not very serious, you might then easily take care of your nails through following of the tips on how to do away with the black lines on nails that we have mentioned above.



  1. How to Get Rid of Black Lines on Nails: The Tips and Causes You Need to Know!:
  2. What Are Splinter Hemorrhages:
  3. What Do Black Lines Under Fingernails Mean? How To Get Rid Of Them:
  4. Melanonychia:
  5. Black Lines in Fingernails & Heart Disease:
  6. This Woman’s Story Shows Why You Should Never Ignore a Black Line On Your Nail:

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