Nail fungus is a common infection of the nail. It begins as a white or yellow-brown spot under the tip of your fingernail or toenail. As the fungal infection goes deeper, the nail may discolor, thicken and crumble at the edge. Nail fungus can affect several nails.Symptoms of nail fungus include a nail or nails that are: Thickened Discolored Brittle, crumbly or ragged Misshapen Separated from the nail bed Smellyou may want to see a health care provider if self-care steps haven’t helped and the nail becomes increasingly discolored, thickened or misshapen. Also talk with your health care provider if you have: Diabetes and think you’re developing nail fungus Bleeding around the nails Swelling or pain around the nails Difficulty walking
https://www.mayoclinic.org/diseases-conditions/nail-fungus/symptoms-causes/syc-20353294