Respiratory

Hypopneas & RERAs

Partial airflow reductions tied to desaturation or arousal, and effort-related arousals.

Educational reference, not a diagnostic tool. A scored event, an elevated index and a clinical diagnosis are different things. Follow your facility’s scoring manual, notification policies and clinical protocols.

Check the hypopnea rule your lab uses (3% vs 4%).
RERAs show flattening or effort increase ending in arousal.

Waveforms

Hypopnea: 1A, arousal pathway

reviewed

Respiratory

Synthetic adult PSG teaching tracing showing airflow and chest effort amplitude reduced by 50% for 16 seconds, followed by an EEG arousal. — Illustrative teaching waveformExample: 50% airflow-amplitude reduction for 16 seconds.Source: Original synthetic teaching signals. Not patient data. Not a diagnostic tracing.

Hypopnea: 1A, 3-point oxygen drop

in-review

Respiratory

Supplied synthetic hypopnea illustration labelled 50% airflow reduction for 16 seconds, with oxygen falling from 96% to 93% and no EEG arousal shown. — Illustrative teaching waveformSupplied example: 50% airflow-amplitude reduction for 16 seconds; oxygen 96% to 93%.Source: Original synthetic teaching signals. Not patient data. Not a diagnostic tracing.

Hypopnea: 1B, 4-point oxygen drop

reviewed

Respiratory

Synthetic adult PSG teaching tracing showing airflow and chest effort amplitude reduced by 50% for 16 seconds with oxygen falling from 96% to 92% and no EEG arousal. — Illustrative teaching waveformExample: 50% airflow-amplitude reduction for 16 seconds.Source: Original synthetic teaching signals. Not patient data. Not a diagnostic tracing.

Obstructive hypopnea

reviewed

Respiratory

Synthetic adult PSG teaching tracing with flat-topped inspiratory airflow, continuing chest effort and out-of-phase abdomen effort during a 16-second event. — Illustrative teaching waveformFlattened inspiration with continuing effort; new paradox is shown.Source: Original synthetic teaching signals. Not patient data. Not a diagnostic tracing.

Central hypopnea

reviewed

Respiratory

Synthetic adult PSG teaching tracing where airflow, chest effort and abdomen effort all fall by 50% together for 16 seconds, with a flat snore sensor. — Illustrative teaching waveformAirflow and effort decrease together; breaths remain rounded.Source: Original synthetic teaching signals. Not patient data. Not a diagnostic tracing.

RERA

reviewed

Respiratory

Synthetic adult PSG teaching tracing showing 16 seconds of flattened airflow ending in a 4-second EEG arousal, without a 4% oxygen drop. — Illustrative teaching waveformFlow limitation ends with an arousal; apnea and hypopnea criteria are not met.Source: Original synthetic teaching signals. Not patient data. Not a diagnostic tracing.

Related calculators

AHI RDI