There are different classifications of nail fungus — depending on type of fungus and manifestation — which may have somewhat different signs and symptoms. In general, however, you may have a nail fungal infection — also called onychomycosis (on-i-ko-mi-KO-sis) — if one or more of your nails are:

  • Thickened
  • Brittle, crumbly or ragged
  • Distorted in shape
  • Dull, with no luster or 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. You may feel pain in your toes or fingertips and detect a slightly foul odor.

When to see a doctor

Once a nail fungal infection begins, it can persist indefinitely if not treated. See your doctor at the first sign of nail fungus, which is often a tiny white or yellow spot under the tip of your nail.

Aug. 25, 2011