Black Fingernail Streaks - Health Inspiration

Having a dark line on your fingernails or toenails is called melanonychia. The lines are brown or black and usually look like a stripe that begins at the bottom of your nail bed and continues to the ... Black or brown lines appearing on fingernails or toenails are a common finding and are often dismissed as cosmetic changes (1 Trusted Source Melanonychia: Etiology, Diagnosis, and Treatment Go to ...

MSN: Black Line on Your Nail: Causes and When To Seek Care Melanonychia, a black line on your nail, can be a sign of melanoma or benign pigmentation changes. Injuries, medications, and conditions like hyperthyroidism may also cause dark lines on your nails.