Just wondering if anyone on here has experienced or heard of low O2 saturation as a result of heavy caffeine use? Either my pulseox is having a fit or something's kind of wrong. HR 46 and O2 @ 78. Hoping this is just temporary but I've never seen it this low. Also had some palpitations for a few seconds. 20y/o male. About 32oz dark coffee taken in over 6h. No idea of the content of the particular brand I'm using, but according to mayo I guess it could have been up to 800mg if it was 200mg/cup. They also claim up to 400mg is safe for adults. Well then... Edit: HR back up to 99 with O2 @ 97. Weird little episode there. Could also just be the acidity of coffee in general causing a temporarily decreased Hg affinity (hypoxia through acidemia). But I've never particularly heard of caffeine/coffee causing hypoxia. In fact, there's a paper on treating infants with IH where caffeine helps decrease hypoxia (ref: http://www.ncbi.nlm.nih.gov/pubmed/24445955). It also prevents hypoxia-induced perinatal white matter injury (ref: http://www.ncbi.nlm.nih.gov/pubmed/17044013). So I'm inclined to think it is the acidity, then? Not sure. This, mind you, happened not after the bulk of the dose, but after a short couple sips following about a 2-3h break from consumption. I did walk around a bit beforehand, but not heavily. Any ideas? I've had similar episodes before but never actually quantified what was going on, as I did this time.