Is 5 minutes of oxygen level below 90% while sleeping every night bad for you? i suffer from sleep apnea? i wear continuous pulse oximeter every night?

If it is 5 continuous minutes, that is more of an issue than if it is one minute at a time and it adds up to 5 minutes over the course of the night. If you are using CPAP or BiPAP, perhaps it needs to be adjusted if you are still having a pulse ox of less than 90% for 5 minutes at a time. Let your doctor know so that adjustments can be made if needed. Good luck!