Your machine doesn't just count events, it sorts them by type. CPAPGeeks shows each type in its own color on the charts and in the event list. Here's what each one means.
Obstructive apnea
Your airway collapses and air stops flowing for 10 seconds or more, even though your body is still trying to breathe. This is the classic event of obstructive sleep apnea, and it's what CPAP pressure is designed to prevent.
Central apnea
Air stops flowing for 10 seconds or more, but this time the airway is open: your brain briefly didn't send the signal to breathe. A few central apneas are common, especially when falling asleep or just after a big breath. If you see a lot of them, mention it to your clinician, because they're treated differently from obstructive apneas.
Hypopnea
Airflow drops a lot, but not completely, for 10 seconds or more. You keep breathing, just shallowly. Hypopneas count toward your AHI along with apneas.
Unclassified apnea
An apnea the machine couldn't confidently label as obstructive or central. In CPAPGeeks, every apnea from a Sefam machine appears this way, because the machine doesn't record the type.
Arousal (RERA)
A respiratory effort-related arousal: increasing effort to breathe that ends with a brief wake-up, without a full apnea or hypopnea. Arousals don't count toward AHI, but many of them can leave you tired.
Periodic breathing (Cheyne-Stokes)
A repeating pattern of breathing that slowly grows deeper, then shallower, sometimes with pauses. Some machines flag stretches of it. It's worth raising with your clinician if it appears often.
Why the type matters
Obstructive events usually respond to pressure; central events often don't, and can even increase with too much pressure. That's why the mix matters as much as the total. When you talk to your clinician, a few screenshots of events from CPAPGeeks make the conversation much easier.
Want to see them for yourself? Our guide to reading your flow chartshows what each event looks like.