Millions of Canadians have sleep apnea, but many are unaware of their condition. Sleep apnea can lead to various health problems if left untreated, including heart disease, diabetes, and high blood pressure. There are two main types of sleep apnea: obstructive sleep apnea, which is caused by a collapse of the upper airway, and central sleep apnea, which is a brain signal problem. Diagnosis of sleep apnea often involves in-lab testing, but home sleep apnea testing is becoming more common. The main treatment for sleep apnea is a continuous positive airway pressure (CPAP) machine.