Obesity is a rapidly growing social problem that affects more than 650 million people worldwide. It has been proven that obesity is associated with diabetes mellitus, dyslipidemia, hypertension, cardiovascular diseases, obstructive sleep apnea (OSA) syndrome. However, one of the most serious and least reported complications is obesity-hypoventilation syndrome, characterized by obesity (body mass index ≥ 30 kg/m2), hypercapnia (PaCO2 > 45 mmHg), as well as respiratory disorders during sleep (AHI > 5h). The prevalence of OHS is estimated at 10–20% in obese patients. The basis of the pathogenesis of OHS is low compliance of the chest and lungs due to excessive weight load. An effective method of treatment is to change the life-style in order to reduce body weight, however, there are frequent cases of acute respiratory failure (ARF), for the correction of which respiratory support is necessary, in particular with the help of non-invasive ventilation (NVL). For this purpose, an artificial ventilation device is used with various modes of operation: continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP), average volume-assured pressure support (AVAPS). At the same time, obstructive phenomena are not attributed to the main causes of OHS, which is why CPAP is not conceptually a method of treating OHS, however, it was found that more than 90% of patients with OHS have concomitant OSA. In such patients, most of the pathophysiological links can be safely corrected using CPAP therapy, since with this method the stability of the upper respiratory tract lumen is achieved. BiPAP and AVAPS regimens affect the pathogenetic mechanisms of OHS, which is why they demonstrate high effectiveness both in the short term (ARF) and in the long term (long-term treatment with respiratory support).