A nail fungus infection is a common condition that can change the appearance of the nails. This can make the nails appear discolored, jagged in the edges, brittle, and crumbly. The medical name for this condition is onychomycosis. It affects the same way as athlete’s foot; but instead of affecting the skin on the bottom of the feet or in between the toes, the fungus invades the nails. Fungi are minute organisms that can only be observed by using a microscope.
Nail fungus symptoms differ depending on the type of nail infection you have. They may start mild at first and become worse over time. You may see at first a white or yellow spot underneath the nail. Over time, this may spread and make the entire nail yellow, white, green, or black. The nail may become thick and hard to cut. It may also curl up or down and loosen from the nail bed. In some cases, the infected nail may become painful and emit a foul smell.