What illnesses do fungi cause?

Fungi cause a wide range of health problems which are very generally referred to as fungal infections. 

Most fungal infections appear as skin rashes. Fungal infections may also occur in the lungs. Rarely, fungal infections affect the blood or the lining of the brain (fungal meningitis). 

The most common fungal infection is a yeast infection (commonly referred to as thrush), which can occur in the mouth, skin, or genitals. Thrush is caused by an overgrowth of the fungus Candida albicans. In the mouth, thrush appears as a white coating on the tongue or gums. If left untreated, the tongue and gums will become painful and may begin to bleed. 

Thrush and other fungal infections are treated with antifungal medications which can be administered orally or applied to the skin as a topical cream.