Histoplasma is a type of fungus that can cause an infection known as histoplasmosis. It thrives in environments rich in organic material, particularly in areas with bird or bat droppings. When the spores are inhaled, they can lead to respiratory issues, although many people may not show symptoms. The infection is more common in certain regions, especially in the Ohio River Valley and parts of Central America. Most cases are mild and resolve without treatment, but severe cases can occur, particularly in individuals with weakened immune systems. Diagnosis typically involves laboratory tests to identify the fungus.