Fungi are simple organisms found almost everywhere in nature.
These fungi often cause diseases in the plants and animals they infect. The most common fungal diseases in people are skin infections, such as ringworm or athlete's foot. These conditions can be caused by a number of fungi, including species in the groups Trichophyton, Microsporum, and Epidermophyton. Other fungi that normally live harmlessly in the body can sometimes cause disease. For example, fungi in the Candida group, which commonly inhabit the mouth, bowel, or vagina, can cause a variety of disorders, including a disease of the throat called thrush.