The most common fungi to cause skin infections are the tinea group of fungi. For example, athlete's foot (tinea pedis) is a common fungal infection of the toes and feet. Tinea infection also causes ringworm (tinea corporis) and ringworm of the scalp (tinea capitis) . It also causes many fungal nail infections . A common fungal infection of the mouth and of the vagina is called thrush. This is caused by an overgrowth of candida which is a yeast (a type of fungus). Small numbers of candida commonly live harmlessly on the skin. However, certain conditions can cause candida to multiply and cause infection . Candida is also sometimes the cause of some fungal nail infections.