Thickened nail
Yellow, white, or brown discoloration
Brittle, crumbly, or ragged nail edges
Distorted nail shape
Nail lifting from the nail bed
Debris buildup under the nail
Dull or cloudy nail surface
Foul odor from the nail
Nail becoming hard to trim
Spreading to other nails
Itching or irritation around the nail
Pain or discomfort, especially with pressure