Medically reviewed by Susan Bard, MD Melanonychia, a black line on your nail, can be a sign of melanoma or benign ...

If you have noticed lines that appear like grooves or indentations running horizontally across your fingernails or toenails, you may be wondering what's going on. These are known as "Beau's lines." ...

White spots on nails (known as leukonychia) are a common condition that may affect one nail or multiple nails. Leukonychia may appear as spots, bands, or streaks. Leukonychia is generally harmless and ...

DEAR DR. ROACH: I have a serious problem with my fingernails splitting and coming off at the edges. I have tried biotin and keratin for almost a year without results. I am an 89-year-old man who takes ...