AHI Calculator - Apnea Hypopnea Index

The Apnea Hypopnea Index, usually abbreviated AHI, summarizes how often breathing stops or becomes significantly reduced during sleep. An apnea is a pause in airflow that meets a study's scoring criteria, while a hypopnea is a partial reduction in airflow associated with oxygen desaturation or arousal. The index combines both event counts and divides the total by hours of actual sleep, producing an average number of events per hour. For adults, an AHI below 5 events per hour is generally considered within the normal range. Values from 5 to below 15 are commonly categorized as mild, 15 to below 30 as moderate, and 30 or more as severe. These categories help describe obstructive sleep apnea severity, but the number alone does not capture every clinically important feature. Oxygen saturation, duration of events, sleep stage, body position, cardiovascular conditions, daytime sleepiness, and whether events are obstructive or central can change the interpretation. Use total sleep time rather than the total time spent in bed whenever a sleep study provides it. Polysomnography measures sleep directly, while many home sleep apnea tests report monitoring or recording time instead. Using a longer recording time when the person was awake can underestimate the event rate. Scoring rules also differ between laboratories, sensors, and guidelines, so results from separate studies may not be perfectly comparable. A respiratory event index from a home test may therefore resemble AHI but should retain the name and denominator used in the report. This calculator performs the arithmetic used to derive AHI from known event counts. It does not diagnose sleep apnea and cannot replace a complete sleep report or professional evaluation. A clinician may diagnose clinically meaningful disease even when a single index is near a category boundary, and pediatric thresholds differ substantially from adult thresholds. Treatment may involve positive airway pressure, oral appliances, positional therapy, weight management, surgery, or management of contributing conditions, depending on specialist assessment. People with loud habitual snoring, witnessed pauses, choking during sleep, severe daytime drowsiness, resistant hypertension, or safety concerns from sleepiness should seek medical assessment. Treatment decisions depend on the complete clinical context, not solely on the calculated category.