Does blackened nails indicate onychomycosis?
Disease description:
My nails appear slightly blackened—online sources say this is “gray nail,” but does nail discoloration to black indicate gray nail?
Doctor's answer (1)
Dr. Liu Wan
Blackened nails are not necessarily “ringworm of the nail” (onychomycosis). Onychomycosis is a common fungal infection of the nail, caused by dermatophytes or yeasts—most frequently *Trichophyton rubrum* or *Candida albicans*. It typically manifests as yellowish-brown discoloration and brittleness or crumbling of the nail plate. The infection usually begins at the distal (free) edge of the nail and may progress proximally, producing irregular, frayed, or “spiky” changes along the nail margin. Although onychomycosis most commonly presents with yellowish-brown discoloration, it can occasionally appear black—particularly when caused by *Trichophyton rubrum* or *Candida albicans*.
