AHI Calculator
Calculate Apnea-Hypopnea Index to assess sleep apnea severity from sleep study data
Calculate AHI Score
Complete cessation of breathing for >10 seconds
Reduction in airflow with oxygen desaturation
Total hours of actual sleep (TST)
Additional minutes of sleep time
AHI Score & Severity
Formula Used
AHI = (Apnea Episodes + Hypopnea Episodes) ÷ Total Sleep Time (hours)
AHI = (0 + 0) ÷ 0.00 = 0.0
Clinical Recommendation
Continue maintaining healthy sleep habits. No treatment needed.
AHI Score Interpretation
0-4: Normal (No significant sleep apnea)
5-14: Mild sleep apnea
15-29: Moderate sleep apnea
30+: Severe sleep apnea
Example: Sleep Study Results
Patient Sleep Study Data
Total sleep time: 7 hours 30 minutes
Apnea episodes: 45 events (complete airway obstruction)
Hypopnea episodes: 75 events (partial airway obstruction)
Total respiratory events: 120 events
AHI Calculation
AHI = (45 + 75) ÷ 7.5 hours
AHI = 120 ÷ 7.5 = 16.0 events per hour
Diagnosis: Moderate Sleep Apnea
Recommendation: CPAP therapy strongly recommended
AHI Classification
Sleep Apnea Risk Factors
Obesity (BMI > 30)
Male sex (2-3x higher risk)
Family history of sleep apnea
Large neck circumference (>17" men, >16" women)
Advanced age (>40 years)
Sedatives, alcohol, or narcotics
Heart disease or stroke history
Treatment Options
CPAP Therapy
Continuous Positive Airway Pressure - gold standard treatment
Lifestyle Changes
Weight loss, sleep position therapy, avoiding alcohol
Oral Appliances
Mandibular advancement devices for mild-moderate OSA
Surgery
UPPP, hypoglossal nerve stimulation for severe cases
Understanding the Apnea-Hypopnea Index (AHI)
What is AHI?
The Apnea-Hypopnea Index (AHI) is a diagnostic metric used to assess the severity of obstructive sleep apnea (OSA). It measures the average number of respiratory events (apneas and hypopneas) per hour of sleep during a sleep study.
Types of Respiratory Events
- •Apnea: Complete cessation of airflow for ≥10 seconds
- •Hypopnea: Significant reduction in airflow with oxygen desaturation
- •RERA: Respiratory effort-related arousals (not included in AHI)
Clinical Significance
AHI Formula: (Apneas + Hypopneas) ÷ Total Sleep Time (hours)
Normal sleep: <5 events per hour
Health Consequences
- Cardiovascular: Hypertension, heart disease, stroke
- Metabolic: Diabetes, obesity, metabolic syndrome
- Neurological: Cognitive impairment, depression
- Quality of Life: Daytime sleepiness, fatigue
- Safety: Increased accident risk, impaired driving
💡 Important: AHI is measured during polysomnography (sleep study) conducted in a sleep laboratory or with home sleep testing.
⚠️ Medical Disclaimer
This AHI calculator is for educational purposes only and should not replace professional medical evaluation. Sleep apnea diagnosis requires proper sleep study interpretation by qualified sleep medicine specialists. AHI is just one component of comprehensive sleep disorder assessment. If you suspect sleep apnea, consult with a healthcare provider or sleep specialist for proper evaluation and treatment. This tool cannot diagnose medical conditions or recommend specific treatments.