Overnight Polysomnography (Sleep Study)

Comprehensive overnight sleep study recording brain waves, oxygen levels, heart rate, breathing, and body movements to diagnose obstructive sleep apnoea, insomnia, restless leg syndrome, and other sleep disorders.

Polysomnography (PSG) is the gold-standard diagnostic tool for sleep disorders, conducted overnight at the Nuffield Sleep clinic in Wheelock Place. During the study, a range of physiological parameters are continuously recorded: electroencephalography (EEG) to capture sleep architecture and detect abnormal brain activity during sleep; electrooculography (EOG) to track eye movements and differentiate REM from non-REM sleep; electromyography (EMG) of the chin and legs to detect muscle activity, periodic limb movements, and REM sleep behaviour disorder; electrocardiography (ECG) to monitor cardiac rhythm; pulse oximetry to track blood oxygen saturation; thoracic and abdominal respiratory effort bands; and an oronasal airflow sensor. This multi-channel recording enables the Nuffield Sleep team to identify and classify sleep-disordered breathing events (apnoeas and hypopnoeas), calculate the apnoea-hypopnoea index (AHI), and determine appropriate treatment pathways. Patients presenting with suspected obstructive sleep apnoea may proceed to a CPAP titration study, where the optimal positive airway pressure setting is determined in a single attended night. Split-night studies — diagnostic in the first half and CPAP titration in the second — can also be performed when the diagnosis is clear from early data. The multidisciplinary team at Nuffield Sleep reviews each study in the context of the patient's full clinical history, enabling integrated recommendations that may span ENT surgical review, CPAP therapy, CBT-I for comorbid insomnia, or nutritional support.