BP in single digits?

December 29, 2010 3:36 PM

Blood pressure measurement in single digits?

I was feeling pretty sick last week (body aches, cough, fever) while at work so I went to a walk-in clinic. While the doc was doing her exam, I started feeling really faint, so she took my blood pressure. By this time I was nearly passing out, but I'm sure she said "Your blood pressure is 2, the minimum is 7". Now, I've only ever heard of blood pressure being measured as a fraction, not as a single digit. Has anyone else heard of this? It was a normal measurement (i.e, the cuff on the upper arm).

As an aside, how can I get my BP at a normal level? Would drinking more water help? (I know I can forget to keep hydrated).

Thanks all!

posted by cozenedindigo to health & fitness (20 answers total)

I'm sorry, but I think you must have misheard. Low blood pressure is defined (at least in the US) as systolic (first number) below 90 or diastolic (second number) below 60. Did the walk-in clinic suggest a follow-up visit?
posted by lukemeister at 3:53 PM on December 29, 2010

Well, 2 is a fraction; e.g. 100/50. That said I agree that you likely misheard.
posted by dfriedman at 3:55 PM on December 29, 2010

Are you a zombie? A blood pressure of 2 means you're dead, and the 2 is a measurement error. I suppose being bitten by a zombie would also explain the body aches, cough and fever.
posted by chengjih at 3:56 PM on December 29, 2010 [6 favorites]

We can't give you any links or other resources on how to raise your blood pressure without knowing what your blood pressure actually is. "2" and "7" are not blood pressure measurements (understandable that you misheard given how crappy you were feeling!) so hard to know how significant an issue you're looking at.
posted by Sidhedevil at 4:02 PM on December 29, 2010

In the early morning mine is occasionally so low it can't be measured at all. Or they get some goofy reading like "11 over 2". This is just regular checkups too, I'm not sick at the time.
posted by fshgrl at 4:06 PM on December 29, 2010

Now, I've only ever heard of blood pressure being measured as a fraction, not as a single digit

It's not a fraction. Those are two separate numbers: the systolic and diastolic pressures. The 'over' is merely a reporting convention.
posted by mr_roboto at 4:09 PM on December 29, 2010 [2 favorites]

Blood pressure in France (and many metric countries) is measured in MPa (Megapascals), but that wouldn't convert out properly either.
posted by blue_beetle at 4:10 PM on December 29, 2010

Yes, chiming in to say a BP of 2/7 = dead. BP is I think one of the things that has the same measurements internationally.

Could she have been talking about a pulse rate? A lot of BP machines measure pulse rates at the same time as blood pressure. The numbers are still way too low for you still to be alive, but it is a single digit. The other thing is that your pulse rate slows down as you faint, and you mention being on the verge of passing out. Against this is that your pulse tends to speed up when you're generally ill. Though from the sound of the state you were in, she might have been talking about the battery meter on the BP machine, or something else entirely!

If you're still feverish and coughing, treat those things. Otherwise, both blood pressure and pulse rate can change a lot while you're ill; you want a measurement when you're well before you start worrying about things.
posted by Coobeastie at 4:15 PM on December 29, 2010

Well, I've always got my blood pressure in mmHg. But there isn't a reason they couldn't do inHg. So 2in ~ 50mm and 7in ~ 177mm. That sounds like a huge range though, and 177mm is dangerously high.
posted by sbutler at 4:26 PM on December 29, 2010

I too have extremely low blood pressure. After fainting a number of times and running a series of tests to make sure these incidents weren't due to something more severe, my doc recommended simply eating more sodium. It's so simple, but when I am feeling faint, shaky, or weak, a small bag of pretzels or something with soy sauce will make me feel better almost instantly. Doing so raises your bp a bit to what is probably a normal level for most.
posted by shrimpsmalls at 5:55 PM on December 29, 2010

But there isn't a reason they couldn't do inHg.

Not enough granularity, as you point out.
posted by Sidhedevil at 6:12 PM on December 29, 2010

I have very low blood pressure, so much so that nearly every technician takes my bp twice. Today it was 93 over 45. Due to my low bp, I have a tendency to faint if I'm standing still for too long. Sodium indeed does the trick.
posted by two lights above the sea at 6:22 PM on December 29, 2010

It's possible she has her instrument set to different units. I would think in this case cmHg would be the most probable. If it was a manual reading the gauge may be ticked in mm but labeled in cm. A diastolic reading of 70mmHg (7cmHg) is pretty low for most people and is the point where I feel quite dizzy. If you have small arms the reading may be artificially low so an already low reading may show the minimum.
posted by Yorrick at 8:25 PM on December 29, 2010

Your profile says you're in Canada, which is mostly metric, but apparently still uses mmHg for blood pressure.

It's possible to survive a blood pressure of 2 kiloPascal (kPa, not MPa) and some metric countries like Spain use that as an alternative unit. 7kPa is about 52 mmHg, which would a reasonable lower bound on normal diastolic blood pressure.

Yorrick, you wouldn't (and usually can't) just set a sphygomanometer to read out in any units you please, and even if the instrument read out in an odd unit the operator would convert it to a standard one before reporting it.

IANAD but I have many family members with hypertension, heart problems, and other conditions that require them to monitor their blood pressures.
posted by d. z. wang at 3:20 PM on December 30, 2010

Oops, sorry Yorrick, on post I see that it was sbutler suggesting inches of mercury.
posted by d. z. wang at 3:21 PM on December 30, 2010

Yorrick, a diastolic of 70 is pretty normal. You must be thinking of systolic.

Anyone who thinks their blood pressure has ever been read at this low is probably mistaken. An automatic cuff wouldn't make a mistake that extreme, and anyone who's taking the blood pressure manually will start deflating the cuff quickly and retry the pressure before they get that low, because a systolic reading below 60 or 70 is not consistent with an alert, talking person. It would be difficult to get blood flow to your brain with that pressure, and to go much lower than that, you'd have to basically stop your heart from beating.
posted by treehorn+bunny at 6:24 PM on December 30, 2010

Oh I know mine isn't that low, it's just low enough at times to screw up the machines which give some kind of minimum or error reading (that I'm dead) and low enough they can't always get it manually.

And it really is that low, so is my heartbeat. If you leave me hooked up to a monitor and I just lay there and don't move or fall asleep all the alarms will go off. Everything is normal if I'm up and moving around though.
posted by fshgrl at 3:42 PM on December 31, 2010

Thanks everyone for the answers (especially the zombie comment....ha!) I'm thinking I must have misheard, and I'll try and get a proper reading in the near future.
posted by cozenedindigo at 7:36 AM on January 2, 2011

Please keep us posted, cozenedindigo!
posted by lukemeister at 11:17 AM on January 3, 2011

Ok! I clearly misheard the doc. I got a proper reading yesterday, and my BP was 121/68. So, a tad low but nowhere near dead! ;)
posted by cozenedindigo at 6:15 PM on January 3, 2011 [1 favorite]