The BAL for Fungus C/S with Fungus Stain (KOH) is requested when a healthcare provider suspects that a patient may have a fungal respiratory infection, which can cause symptoms such as coughing, wheezing, shortness of breath, chest pain, and fever. Fungal respiratory infections can occur in people with weakened immune systems due to conditions such as HIV/AIDS, cancer, or diabetes, as well as in people who have inhaled contaminated fungal spores in the environment.