Are black or yellow toenails a sign of onychomycosis (fungal nail infection)?
Disease description:
My toenails have been turning black and yellow for some time—there’s no pain or itching—but there’s also a vertical discolored streak. Could this be onychomycosis (fungal nail infection)?
Doctor's answer (1)
Dr. Liu Wan
Blackish or yellowish discoloration of the toenails may sometimes indicate onychomycosis (fungal nail infection). Following nail trauma or infection, individual variations can lead to black or yellow discoloration. This condition may also be subungual melanoma—a benign skin tumor—though most cases remain stable, with only a minority undergoing change. Patients should visit a hospital for fungal microscopy; a positive result confirms the diagnosis of onychomycosis (a fungal infection).
