Acceptable O2 levels while sleeping?

I recently got an oximeter, and have been monitoring my O2 levels. While exercising, I stay above 96. Normally during the day (sitting, walking, etc.) I stay between 94-96. At night while sleeping I seem to fluctuate between 90-93. My heart rate while sleeping is anywhere between 48-60.

Are my O2 levels while sleeping something to worry about?

Im 32, in generally good health, dont smoke, rarely drink, no caffeine. I've been getting treatment for a herniated disc in the neck (decompression), and have been diagnosed several times in the past few months with Costochondritis. I occasionally (once every few weeks) have shortness of breath issue during the day (the reason I got the oximeter).

I have a physical scheduled in the next few weeks, I just want to be prepared with good questions.

[whisperwolf]

Hello. There is no hard and fast rule to O2 Saturation levels, but generally the doctors will want to see levels above 90%. Your pulse rate while sleeping is probably fine as well.
So may I ask why you were monitoring your O2 saturation in the first place? Curious or did some symptoms trigger concerns?

[seinarsson]

My wife is dealing with some asthma issues and got an oximeter to monitor herself during exercise. I checked mine a few times just out of curiosity, and found it lower than I would have thought.

Combine that with the Costochondritis and occasional shortness of breath issues I've been having, and I figured I'd monitor it at night a few times just to be safe.

The only thing I *know* is wrong with me is the herniated disc in my neck, but I can't get any straight answers as to if that is the cause of the Costochondritis and shortness of breath.