Hi is black lines in your nails a cause for concern?

Medical exam: The explanations for black lines on your nails can range from something which is normal through to severe, such as melanoma. Certain medications, HIV, Lupus & scleroderma are among other possible causes. I strongly encourage you to go to a medical clinic for a full exam to have the cause of your condition properly diagnosed & treated if necessary.

Sometimes: Black stripes down 1 nail may be subungual hematoma. Red or brown streaks may be splinter hemorrhages. Brown/black lines from nail plate to tip are often seen in people with dark skin & are normal. Subungual Melanoma can cause nail ridges & dark colors of cuticle. It most often effects the thumbs or big toes. Dark lines may be due to other illnesses. Get checked out when in doubt.