As the prevalence of obesity increases in both the developed and the developing world, the respiratory consequences are often underappreciated. This review discusses the presentation, pathogenesis, diagnosis and management of the obstructive sleep apnoea, overlap and obesity hypoventilation syndromes. Patients with these conditions will commonly present to respiratory physicians, and recognition and effective treatment have important benefits in terms of patient quality of life and reduction in healthcare utilisation. Measures to curb the obesity epidemic are urgently required.

Noninvasive ventilation is effective in the treatment of patients with severe acidosis due to acute hypercapnic COPD.

Sleepiness, particularly related to shift work, needs to be emphasized as a risk factor for MVC. Australian Transport Safety Bureau definitions of sleep-related MVC are too lenient.