Fungi can live in a variety of environments, including the air, soil, water, and plants. Some fungus can also be found naturally in the human body. There are beneficial and detrimental fungus, just like there are beneficial and hazardous microorganisms. When pathogenic fungi infiltrate the body, they can be difficult to eradicate since they can persist in the environment and re-infect the individual who is attempting to recover. Infections caused by fungi are frequent in many parts of the natural world. Fungal infections in humans occur when an invasive fungus takes over an area of the body and overwhelms the immune system. Anyone can have a fungus infection, and they can arise in any region of the body.