Overview
Onychomycosis is a fungal infection of the fingernails or toenails. Fungal infections are caused by different kinds of yeast and fungi that are different than bacteria. The infection can affect any part of the nail: the nail itself, underneath the nail, or the cuticle. Unlike a bacterial infection, fungal nail infections are usually not painful but they do disrupt the normal growth of the nail and change the appearance of the nail, often making the nail look white or crumbly. Fungal nail infections may be difficult to treat, and topical antifungal drugs will usually not cure the nail condition; you will need to speak to your doctor about effective treatment. Fungal nail infections are contagious, particularly to people with problems with their immune systems, so it is important to wash your hands thoroughly and carefully and to not share towels or other intimate objects with others.
