Final answer:
Sleep apnea diagnosis is confirmed through a sleep study in a laboratory where various bodily functions are monitored.
Step-by-step explanation:
A diagnosis of sleep apnea is usually confirmed through a sleep study conducted in a sleep laboratory. During the study, the patient's blood oxygen levels, heart rate, respiratory rate, blood pressure, and brain activity are monitored. The volume of air inhaled and exhaled is also measured. This comprehensive monitoring allows doctors to assess the severity of sleep apnea and make a diagnosis.