How is it Diagnosed?
Obstructive Sleep Apnea (OSA) is diagnosed through a combination of clinical history,
physical examination, and objective sleep studies. Patients typically report loud snoring,
witnessed apneas, gasping during sleep, non-restorative sleep, excessive daytime
sleepiness, morning headaches, or cognitive impairment.
Clinical evaluation includes assessment of body mass index (BMI), neck circumference,
tonsillar size, and craniofacial abnormalities that might predispose to airway obstruction.
Screening questionnaires like the Epworth Sleepiness Scale or STOP-BANG are
commonly used to evaluate the likelihood of OSA.
The definitive diagnostic tool is polysomnography (PSG), an overnight sleep study that
records brain activity, eye movements, heart rate, oxygen saturation, airflow, and
respiratory effort. It quantifies the apnea-hypopnea index (AHI), which classifies the
severity of OSA: mild (5–15 events/hour), moderate (15–30), or severe (>30).
Home sleep apnea testing (HSAT) may be used in uncomplicated, high-risk patients but
is less comprehensive than in-lab PSG. Additional investigations may include overnight
oximetry and ECG if cardiac arrhythmias are suspected.
Differentiation from central sleep apnea and other sleep disorders is crucial. Timely
diagnosis and treatment—often involving CPAP therapy, weight loss, oral appliances, or
surgery—can prevent serious complications like hypertension, stroke, and
cardiovascular disease.