The South African population is suffering from an obesity epidemic. Sleep-disordered breathing (SDB), which includes obstructive sleep apnoea and obesity hypoventilation syndrome, is closely related to obesity. SDB may have serious health consequences if not asked about when taking a history related to sleep and sleep-deprivation symptoms. Unfortunately, a formal polysomnogram is available to very few patients who need the diagnosis confirmed. However, taking a sleep history, measuring the haemoglobin level and using a much smaller device in the comfort of a patient's bed can obviate the need for formal polysomnography.