black line on nail

Black Line on Nail: How to Treat This

April 4, 2019

People look for ways to avoid medical conditions that may have adverse effects on their overall health and physical appearance. One such medical condition, which may seem trivial to some people, is the appearance of a black line on the nail. People may naturally ask “What does this black line on my nail mean and how do I treat this?”. In this article, we will look at the possible reasons for the appearance of a black line on the nail.

Black Line on Nail: A General Overview

Splinter hemorrhage is the term used for the black narrow and vertical line that forms under an individual’s nail. Splinter hemorrhages can happen due to a number of different reasons. Some of these reasons may be harmless or they may be a sign of something more serious. Splinter hemorrhages go the name due them looking like splinters wood lodged under an individual’s nails.

Primarily, splinter hemorrhages are caused by tiny blood vessels present underneath a person’s fingernail that get damaged or destroyed. A splinter hemorrhage is usually characterized as appearing on one or multiple locations under the person’s nail, its appearance does not change despite the application of pressure or by pressing it and it is generally described as reddish-brown or black in color.

Other such lines may appear on the nails of individuals such as Beau’s lines. Beau’s line is described as being a horizontal line that runs across the nail and is generally harmless. However, the appearance of beau’s line may be a symptom of much serious health or medical condition such as cancer specifically cancer called subungual melanoma.

Possible Causes for the Appearance of a Black Line on Nail

The appearance of a black line on the nail may be attributed to a number of different reasons. Listed below are some of the possible reasons:


Splinter hemorrhages are commonly caused by trauma which can injury an individual’s nail. This is usually the result of something that may hurt blood vessels found underneath that person’s nails resulting in burst or damaged blood vessels. Patients may also have some form of trauma without initially realizing it such as when tightly gripping or squeezing something.


Splinter hemorrhages may be caused by a heart condition known as endocarditis. Patients who have endocarditis are at fifteen percent (15%) increased risk of developing splinter hemorrhage. The said heart condition occurs when the heart’s inner chambers or valves are infected. Aside from splinter hemorrhage of the black line on the finger, endocarditis can lead to other more serious health and cardiovascular conditions. In addition, endocarditis is usually observed in patients who already have some other form of heart or cardiovascular disease.


The skin condition known as psoriasis may also cause black line on the nail or splinter hemorrhage. Psoriasis may cause scaly skin and silver plaques to build up and accumulate on the patient’s skin. Patients with above-mentioned skin condition are at a fifty percent (50%) increased risk for developing a black line on the nail or splinter hemorrhage.

Various Other Medical Causes

Black line on the nail or splinter hemorrhages can also be caused by a number of different medical issues. These medical issues include chemotherapy side effects, a disease of the lungs, kidneys or circulatory system, Raynaud’s disease, blood clotting medications, lichen planus, nail fungus, lupus, vasculitis and different types of infections.

It may be noteworthy to mention in this article that on the other hand, the appearance of Beau’s lines on all twenty (20) of the patient’s nails may signify some serious underlying medical condition. These include syphilis, type 2 diabetes, thyroid disease, and mumps.

Diagnosis for Black Line on Nail or Splinter hemorrhage

Black line on nail or splinter hemorrhage should immediately be coordinated with the patient’s healthcare partner or doctor if he or she believes that the splinter hemorrhage was not directly caused by trauma. In addition, splinter hemorrhage that may have been caused by trauma or injury but does not resolve on its own after a few weeks may also warrant a visit to the patient’s doctor or healthcare partner.

Patients with splinter hemorrhage and who are aware that they also have endocarditis should immediately seek medical attention from their healthcare professional or doctor if they are also experiencing other symptoms such as shortness of breath, joint pain, paleness of the skin, fever, or fatigue. Patients should also seek medical condition for their psoriasis especially if accompanied with symptoms such as the appearance of scales on the skin, patches and rashes on the individual’s skin folds, feet, hands, face, and scalp.

Recurring splinter hemorrhages on one (1) or more nails should also be coordinated with the patient’s doctor or healthcare professional.

Once Splinter hemorrhages are coordinated with the doctor, the healthcare professional will check the medical history of the patient and recommend further laboratory testing to confirm any possible health condition that may be causing the black line on nail condition of the patient.

Treatment Options for a Black Line on Nail

Treatment to be utilized in addressing splinter hemorrhage or black line on the nail will depend largely on the medical condition causing the said health issue. Most of the time, however, patients with a black line on nail or splinter hemorrhages that are not caused by a serious medical condition will go away or resolve on its own. If the splinter hemorrhage is caused by a more serious medical condition, patients are urgently advised to see their doctor as there are no specific treatments for splinter hemorrhages and treatments based on various medical conditions may be specific and customized depending on the patient’s health needs.