Black Lines In Fingernails

Facts about Black Lines in Your Fingernails


Our hands can tell a lot about a person; rough hands belong to manual laborers, smooth hands to desk workers, black lines in your fingernails belong to someone with a medical issue.  Not only is this an unsightly condition, but this condition just may indicate a problem that requires medical attention.


Fingernails are hard plates that are composed of keratin, which is a protein produced by the body, that cover the ends of human fingers and toes.  Animals produce keratin, as well, that forms as claws, horns or hooves depending on the type of animal.  Their purpose is to scratch and performing dexterous acts, protecting our fingers from these rough activities.   For centuries, the fingernails have not only been regarded as a useful tool but as an opportunity for embellishment.  Painting the nails, buffing the nails and piercing the nails to insert precious jewels have long been a vain part of not only the lives of women but of men as well.  Fingernails are so highly considered to be a part of an attractive model that artificial fingernails are frequently purchased in place of growing real nails. 


Growing real nails is a natural process.  New cells grow from the base of the nail, just under the cuticle, in a continual regeneration; pushing the older cells upwards.  These aged cells harden as they emerge.  Healthy nails are translucent; displaying the pinkish tone of the skin underneath in the nail bed.  When certain diseases or conditions are present in the body, they can often be manifested through pattern variations in the fingernails.  When you see black lines in your fingernails, it very likely means that there is a medical condition present that requires attention.  There are several reasons for these lines, including:

  • Splinter Hemorrhages.  One reason for the appearance of black lines could be a condition called “splinter hemorrhages”.  If there has been any type of trauma to the finger, a thin dark line appearing on the fingernail is quite common.  It is not generally a serious condition when caused by trauma and will eventually disappear as the nail grows.  Splinter hemorrhages can also be caused by a more serious condition, however; an infection of the valves of the heart as result of valve damage could be the reason. 

  • Fungus.  Nails are prone to fungus infections, which can be displayed as black lines.

  • Melanoma.  Dark lines that run from the cuticle to the tip of the nail can indicate the presence of nail melanoma; a condition that could mean either a benign or a malignant tumor.

  • Beau’s lines.  A symptom of this condition is a dark line that runs across the breadth of the nail.  It is symptomatic of several things, including side effects from certain medications.

In situations when you are confident that no trauma has occurred that resulted in the dark lines showing on the nails, it is wise to get the opinion of your doctor to ensure that it is not attributable to any type of serious condition.  Because of the severe threat that heart disease and melanoma brings to an individual’s health, any experiences with black lined fingernails should be checked out.


The appearance of our hands does tell a great deal about us.  It can indicate how old we are, what type of work we do on a daily basis and even sometimes give indications of our health, such as in the case of black lines in your fingernails.  For peace of mind and to rule out any serious medical conditions, it is certainly a wise decision to pay attention to what your hands are telling you; the message just may save your life.