I think for many of us, when we think of sleep disordered breathing, sleep apnea comes to mind. But what about upper airway resistance syndrome? UARS is another sleep disordered breathing condition but with some key differences as compared to sleep apnea. Instead of having an apnea and then arousal, with UARS the person briefly wakes up after not being able to breath well. So, it's considered to be between normal sleep and sleep apnea. The risk factors for UARS are also very different, and there can be a stark contrast in the profile of someone with the two conditions.
From what I've read, a lot of testing done for sleep apnea will miss UARS due to the differences how the two conditions manifest themselves in sleep. It seems to me that many people with sleep issues could have actually have UARS, as this condition results in fatigue and unrefreshing sleep.
Just something to consider if you think you might have sleep apnea.
Links:
http://doctorstevenpark.com/tired-of-being-tired-%E2%80%94-the-upper-airway-resistance-syndrome
https://www.sleepassociation.org/upper-airway-resistance-syndrome/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4881892/
