Fungal nail infections, also known as onychomycosis, are caused by an overgrowth of fungi that breaks down the nail tissue, causing the nail to become brittle and discoloured. Fungal nail is a common condition that usually affects toenails more often than fingernails.

Fungal nail can be effectively treated by using antifungal nail lacquers that contain the active ingredient amorolfine hydrochloride which works by disrupting the growth of the fungi causing the infection.