I have had numbers around 5-7 for over a year, and all of sudden last night it was 18.5! What's that about? I didn't feel anything different about the mask or the machine. Also, can someone finally tell me if the CPAP machine is "curing" all the apneas it reports as the AHI number, or are they happening despite the machine? If the machine cannot eliminate the apneas, why are we bothering to use it?