What is this test?
Polysomnography (PSG) is a comprehensive overnight sleep study that records multiple physiological parameters during sleep, including breathing patterns, oxygen levels, heart rate, brain activity, eye movements and limb movements.
Why is it done?
Sleep study is used to: diagnose obstructive sleep apnoea (OSA), diagnose other sleep-related breathing disorders, assess severity of sleep apnoea to guide treatment, and follow up after treatment.
Who may benefit?
- Patients with loud snoring
- Witnessed pauses in breathing during sleep
- Excessive daytime sleepiness
- Unrefreshing sleep
- Morning headaches
- Resistant hypertension
- Suspected sleep apnoea
How is it performed?
Sensors are applied to record breathing, oxygen levels, heart rate, brain activity and leg movements during sleep. You sleep at the clinic overnight. The recordings are analysed the following day.
Patient Preparation
Avoid alcohol and caffeine before the study. Wash your hair (no hair products). Bring comfortable nightwear and any usual medications. Continue medications unless specifically instructed otherwise.
What information does it provide?
Results include the Apnoea-Hypopnoea Index (AHI) which quantifies the severity of sleep apnoea: mild (AHI 5-14), moderate (AHI 15-29), severe (AHI 30+). Oxygen desaturation patterns are also assessed.
