A nasal septal perforation is a hole in the nasal septum -- the tissue that divides the nostrils. Causes of nasal septal perforation include long-term use of decongestant nasal sprays, aggressive nose picking, chronic nose bleeds, nose surgery, cocaine use, and intentional nose piercing. Small perforations can cause a whistling sound when breathing; larger perforations can cause more severe symptoms, including bloody discharge from the nose, discomfort, and breathing problems, among others. Surgery can usually repair the septal perforation. Follow the links below to find WebMD's comprehensive coverage about nasal septal perforation, what it looks like, how to treat it, and much more.