In severe cases the patient needs to be fitted with a respiratory aid. This so-called CPAP device allows ventilation with slightly elevated pressure over a nasal mask. This therapy leads to decreasing symptoms of the apnea symptoms and the day symptoms. Overweight patients are in many cases finally able to lose weight after therapy initiation since they were too exhausted before. The final goal of the mask treatment is to modify the other factors in a way that the respiratory aid may be stopped again.