Blastomycosis is a fungal infection caused by the organism Blastomyces dermatitidis. This fungus is typically found in moist soil and decaying organic matter, particularly in areas near rivers and lakes. People can become infected by inhaling the spores, leading to respiratory symptoms. Symptoms of blastomycosis can include cough, fever, and chest pain. In some cases, the infection can spread to the skin or bones, causing additional complications. Diagnosis is usually made through laboratory tests, and treatment often involves antifungal medications to help clear the infection from the body.