You may have nail fungus — also called onychomycosis (on-ih-koh-my-KOH-sis) — if one or more of your nails are:
- Brittle, crumbly or ragged
- Distorted in shape
- Dull, with no shine
- A dark color, caused by debris building up under your nail
Infected nails also may separate from the nail bed, a condition called onycholysis (on-ih-KOL-ih-sis). You may feel pain in your toes or fingertips and detect a slightly foul odor.
When to see a doctor
You may want to see a physician if self-care steps haven't helped. Also see a doctor if you have diabetes and think you're developing nail fungus.