The document discusses fungal diseases caused by fungi. It will describe how fungi cause disease and compare different types of fungal infections. There are four main groups of fungal diseases: superficial mycoses which do not involve tissue response; cutaneous mycoses which infect the skin, hair, and nails; subcutaneous mycoses which infect beneath the skin; and deep systemic mycoses which infect deep within the body. Opportunistic mycoses are caused by generally harmless fungi that can cause infection in individuals with weakened immune systems. Common opportunistic infections include candidiasis caused by Candida albicans.