Has anyone heard of MS causing hypoxia or low blood oxygenation? I haven't been diagnosed yet and I'm in the process of having more tests run, but a friend's mom who is a nurse happened to check my blood oxygenation today and it was low. I'm trying to figure out if that leaves MS on the table as a possible diagnosis. The side effect of the hypoxia and the thing that tipped her off is that I sometimes go into tachycardia for brief periods and my reasoning and cognitive abilities are affected at times.