Obstructive sleep apnea (OSA) and sleep-related breathing disorders (SRBDs) are significant health concerns characterized by abnormal breathing during sleep. OSA is typically diagnosed using polysomnography (PSG), with various classifications and monitoring types outlined by the American College of Physicians and the American Academy of Sleep Medicine. Epidemiological studies reveal varying prevalence rates of OSA and SRBD, influenced by diagnostic methods, definitions, and demographic factors. The global prevalence of OSA is notably high in populous countries, with a marked increase in recent years due to aging populations and the obesity epidemic. Epidemiological data show that the prevalence of OSA and SRBD varies by gender, age, and diagnostic criteria, with a generally higher prevalence in men and older age groups. The economic impact of OSA is substantial, with significant costs associated with undiagnosed cases, including lost productivity, motor vehicle accidents, and increased risk of comorbidities. Risk factors for OSA include anatomical features like micrognathia and enlarged adenoids, as well as lifestyle factors such as obesity and alcohol consumption. Postmenopausal women also show an elevated risk. Central sleep apnea (CSA) is less prevalent but more common in older males and those with heart disease. In conclusion, the diagnosis and treatment of sleep apnea syndrome (SAS), encompassing OSA and SRBD, are crucial due to the rising global prevalence and significant economic burden. The overlap of the risk factors for SAS with those for lifestyle diseases underscores the need for increased awareness and understanding for SAS across various medical specialties.