Anything under 90/60 is considered low. It isn't always an issue, but it's not surprising they were fainting, having dizzy spells, etc. with BP that low.

Well, I can assure you I wasn't fine when that 80/40 was measured. 120/80 is considered normal. (And that's right about usual for me. Googling just now, I saw something about them apparently updating the guidelines to 120/70, but that's not that different.) Elite athletes can have resting blood pressures more like 100/something, I think. But I'm no athlete. And having low blood pressure will absolutely render one light-headed, unconscious, or dead. Depending just how low it gets and how long it stays that way. It's not a "lower is better" thing.

I mentioned passing out while watching TV. As soon as I regained consciousness and was still very light-headed, an ambulance was called for me. There were two EMTs. One distracted me while the other took my blood pressure. And took it again. And took it again. And finally asked the other EMT to check, so he took it and was like "no, I think you're getting the right numbers, TootSweet's BP is just low."

When they handed me off to the ER staff at the hospital, he told them he was pretty sure that BP reading wasn't just a bad measurement because I had a lot of "palor" (paleness) at the time.

So, it's probably a reasonable assumption that my BP was a fair amount lower than 80/40 a few minutes before and that 80/40 was taken on the way back up. And the EMTs acted as if 80/40 was not normal or healthy.

Honestly, I largely only mentioned the 80/40 because it was the only test I was given where I got an abnormal result. An ECG, an EEG, EKGs, chest x-rays, Holter monitors, a stress test, a full brain MRI, a calcium score CT scan, multiple rounds of bloodwork (I'm probably forgetting some) -- all those came back "normal" while I was having some of my worst symptoms.

I finally got a doctor who reviewed the results of all those above tests and told me "your nervous system is kindof oversensitive." I had to ask him if he'd just given me a diagnosis of "dysautonomia" and he admittied that "that's not an incorrect term to use for it."

So I guess I've got a half-hearted diagnosis of sorts. Ha! I doubt it's in my chart, though. (I hope you're somewhere more civilized than the U.S.. Medical costs is not at all the only problem with medical care in the U.S..) Much better than my previous doctor who told me it was anxiety. (It wasn't/isn't anxiety.) My previous doctor also swore he'd seen proof that COVID came from a Chinese laboratory, so there's that.

I'm rambling, but in short, not a typo and 80/40 is not somewhere you want to be, I assure you.

What units is that perfectly fine in?

120/80 is perfectly fine, 60/40 is twice less and can't be perfectly fine, 80/40 is much closer to the latter.

Edit: can't find anything regarding what exactly low pressure shouldn't be. Everywhere it says "lower than 120/80" is good. Like okay 0/0 also seems healthy ¯\_(ツ)_/¯