A fungal infection involving the toenails is a common problem that can affect people of all ages, although it most commonly affects older individuals. Toenail fungus often begins as an infection in the skin, commonly known as athlete’s foot. The fungus often starts under the nail fold at the end of the nail. Over time it grows underneath the nail causing changes in the nail’s appearance, such as a yellow or brownish discoloration. It can also cause thickening and deformity of the toenail. Topical or oral anti-fungals are the treatment options for fungal toenails.