fungus is a common nail condition that begins as a white or yellow spot
under the tip of a fingernail or toenail. As the fungal infection goes
deeper, nail fungus may cause nails to discolor, thicken and crumble at
the edge. It can affect several nails.
conditions, such as psoriasis, can mimic a fungal infection of the
nail. Microorganisms such as yeast and bacteria also can infect nails.
Knowing the cause of your infection helps determine the best course of
treatment - topical or oral medications can be used.