The small nasal anatomic area can offer challenges and complications to surgeons and physicians treating chronic rhinosinusitis. This compact, focused publication on Medical and Surgical Complications in Chronic Rhinosinusitis offers clinicians a current source of information to avoid complications and to address them when they arise. Sinus surgery expert and patient champion James Stankiewicz leads this issue with authors who are expert in various aspects of sinus treatment and surgery. Topics include: Overview of complications;  Anatomy of the sinus and complications; Orbital complications and treatment; Neurologic complications and treatment;  Vascular complications and treatment; Smell loss and sinus surgery; Radiology for cases of higher risk of complications; Medication related complications and side effects; Medical-legal issues and complications; Does image guided surgery reduce complications?; Avoiding complications: overriding principles.  Especially dedicated to Residents, Fellows and those in early practice is presentation of External Sinus Surgery and Procedures & Complications; when endoscopic procedures are the norm, how does one handle reversion to an open procedure, which often takes place in emergency situations.