Mushrooms, mildew and yeast are all types of fungi. Of the estimated 1.5 million types of fungi, approximately 300 of them are known to cause health problems in humans, according to the Centers for Disease Control.
Candida is a genus of fungi that can cause thrush and yeast infections. Dermophytes cause fungal infections of the nails and skin, such as ringworm.
There are more than 5,000 types of mushrooms found in the U.S., eight of which are considered to be poisonous. Amanitas, or "death caps," are one type of poisonous mushroom found in the U.S. They are commonly confused with types that are safe to eat, but like the name suggests, they can be deadly.