Why am I only showing 2-3 hours of usage?

I sleep 6-8 hours depending on the day, I've been using my CPAP machine faithfully every time I sleep. I go to sleep with my mask on and only 2 times have I taken it off in my sleep in the 21 days I've been using it. The most time I've ever woken up to see on my "usage" is 3.5 hours. Usually it's only 2 hours or so, if I'm going to sleep with my mask on and waking up with it on... why is my usage showing to be so little? Any ideas? I'm trying really hard to make this work, but I honestly do not notice any difference now than I did before I had this machine. It's frustrating and I want this to work so I can feel like me again. But I'm losing faith fast.

I noticed on my machine's LCD display that it only shows the usage from the last time I turned it off. So if I awake during the night for a bathroom run (around 3 ish in the am), and then turn the machine back on for another 2 or 3 hours, it'll only show that last block of time.

However, when I check the data on sleepyhead or sleep mapper, it combines the time. Sleepyhead even shows you the individual blocks that make up the total.

Which cpap machine are you using and which software?

What are your pressure levels?

Thanks for the input. I have a ResMed, not sure exactly which model, I can look it up when I get back to the house. I start out at 4.0 and ramp up to 9.0 at the moment. I have the version of Apnea where you don't stop breathing, but just breathe really shallow through out the night, thus the low pressure, at least for now. I don't know anything about pulling out my card and reading it. My sleep lab just told me that was for them to do. I would be really interested in seeing that data!! I sure hope I have that situation going on where I'm disconnecting or something... I work swing shifts so I take Ambien to get to sleep and get something close to normal sleep I am hopeful to get away from all that soon though!!

What time do you normally go to sleep and then wake up? Does it happen to be after 12 PM when you wake up?
ResMed machines start a new session at 12 Noon. That could explain the short usage.
Unlikely might be leaks so massive the machine can't sense your breathing and it won't record usage if it doesn't know you are attached.

You can use Sleepyhead to see the data that is collected on your machine. Links in my signature line.

I work swing shifts so

Ditto what Pugsy said, if you sleep till after noon that's the cause. There are ways around it, the good folks here can walk you through it!