Don't understand ahi and need help

I went from 5 ahi to 3.3 ahi in a week since starting my cap treatment. Does anyone know if this is good or bad? Where are you supposed to be at?

Lower is good...below 5.0 is considered acceptable in terms of therapy.
Some people have situations where a little lower seems to let them feel better for whatever reason and that's fine.
In terms of therapy effectiveness...that 3.3 average per hour is well within acceptable limits and for newbies this is especially good because often newbies have more time awake on the machine and sometimes the machine flags awake breathing by mistake....so in terms of sleep time it would be possible for the AHI to be even lower.
Either way 3.3 after a week of therapy...very good.

AHI is an average per hour over the entire night that therapy was being delivered.
And it includes Apneas (both central/CA and obstructive apneas and hyponeas)....so example...AHI of 3.0 over 8 hours means 24 events of some sort over the 8 hours...and not bad at all.
Officially the AHI is the Apnea Hyponea Index and index meaning hourly average.

AHI is the number of apneas and hypopneas you average per hour. As Pugsy mentioned numbers under 5 are considered acceptable - but note that an AHI of 5 still means you are experiencing an arousal every 12 minutes (on average - they actually tend to cluster, so you could conceivably go an hour between events and then have 10 of them the next hour and still have an AHI of 5). So a little lower might be better.

You're off to a great start!!

In the upper right hand corner there is something labeled "CPAP definitions" where I took this from:

AHI/RAI Scale is a measurement of both the Apnea/Hypopnea Index (QHI) and the Respiratory Arousal Index. If a person has less than 5 events per hour then that person's AHI/RAI would be 0 and that person would not have apnea. 5 -15 events/hour = (mild); 15-30 events/hour = (moderate); >30 events/hour = (severe).

As everyone has said, the lower the better!

So are you saying I don't have sleep apnea now or have never because I was diagnosed with obstructive about 3 weeks ago. I thought for sure that I had central sleep apnea because I have multiple sclerosis and have had it for about 15 years now and have been really sick from that for the last few months now. And thank you all for your replies

What was the AHI without a cpap machine? That's what earns the diagnosis...not what the AHI is when using the machine.
AHI when using the machine is just used to gauge the effectiveness in numerical terms of the therapy.

What you have now is TREATED apnea... your numbers are now lower than what you tested in the study because you're using Cpap. If you stop using it, your numbers would go straight back up.

If you had diabetes and your sugar level tested at 600, then you began using insulin and tested at 10, you would still have diabetes (neither that nor OSA go away) but you'd be looking at treated numbers.

OSA doesn't go away by itself, but if you keep using Cpap you can live close to normally with the condition. Stop Cpap and all your symptoms will return.

My ahi has been 0 for the most part now no higher than 2.1 a couple times and 1.1 about three times since I started a month ago with my therapy. Thanks for all the replies.