The following chapter deals with typical complications of noninvasive ventilation (NIV) therapy that can occur during the treatment of a patient. The following chapter lists the serious complications of NIV that carry a risk of death and the less serious complications that can significantly affect patient comfort and compliance. In each paragraph, you will find general tips on how to reduce the risk of the above complications. The most important elements of well-chosen NIV therapy are the use of the treatment in the right patient group by a trained medical team, a clear explanation to the patient of what the therapy is about and what benefits we want to achieve.