Fungal infections are caused by microscopic organisms (fungi) that can live on the skin. They can live on the dead tissues of the hair, nails, and outer skin layers.
Review Date 3/4/2020
Updated by: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.