What Do My Sleep Study Results Mean? A Simple Guide to AHI, Oxygen, and Sleep Stages
You completed your home sleep test, got the report, and now you’re staring at numbers like AHI 18.3, O2 nadir 84%, and sleep efficiency 72%. What does it all mean? Understanding your results is the first step toward effective treatment—and peace of mind.
AHI: Your Apnea Score AHI stands for Apnea-Hypopnea Index. It counts how many times per hour your breathing stops or shallowly dips during sleep. Under 5 is normal. 5–15 is mild sleep apnea. 15–30 is moderate. Over 30 is severe. Your AHI helps determine whether you need therapy and what pressure settings might work best.
Oxygen Saturation: Why Drops Matter Your blood oxygen level should stay above 95% while you sleep. If it dips below 90% repeatedly, your heart and brain aren’t getting enough oxygen. The “nadir” is your lowest reading. Frequent drops signal more severe apnea and higher health risks.
Sleep Stages and Efficiency Healthy sleep cycles through light, deep, and REM stages. Sleep apnea fragments this cycle, reducing restorative deep sleep. Sleep efficiency (time asleep vs. time in bed) below 85% suggests frequent awakenings. Better therapy often restores these patterns within weeks.
What Happens Next If your results show moderate to severe apnea, your provider will likely prescribe CPAP therapy. You’ll get a machine, mask, and setup guidance. Most people see AHI drop to under 5 within the first week of consistent use.
Track Progress, Not Perfection Your first night on CPAP might not be perfect. Leaks, adjustment periods, and new sensations are normal. Focus on trends: Is your AHI dropping? Are you sleeping longer? Feeling more rested? Small improvements add up.
Understanding your sleep study empowers you to take control of your health. For easy at-home testing, clear result explanations, and guided next steps, explore options at cpaprx