Naked Science Forum

Life Sciences => Physiology & Medicine => Topic started by: paul.fr on 24/04/2007 23:30:54

Title: Blood pressure
Post by: paul.fr on 24/04/2007 23:30:54
What exactly is the doctor looking for when he takes your blood pressure, and what do the pressure numbers mean?

also, i have heard of people having high blood pressure, but never low blood pressure! can you have low blood pressure, and what illnesses does it cause?
Title: Blood pressure
Post by: RD on 25/04/2007 15:24:48
can you have low blood pressure, and what illnesses does it cause?

Abnormally low blood pressure is called "Hypotension", it causes fainting.
(High blood pressure is called "Hypertension").

Title: Blood pressure
Post by: Carolyn on 25/04/2007 19:32:07
Paul - My doctors say I have low blood pressure. 

I just took it and it was 117/65, which is actually a little higher than normal for me.  Usually, systolic for me is between 90-100 - generally mid 90's, but it isn't uncommon for it to drop under 90.  Diastolic usually stays between 60-65, but again, not uncommon for it to be under 60.

I've never had any other medical problems as a result.  I was recently told I have fibromyalgia and chronic fatigue syndrome (which I refuse to accept), both of these are common with people who have low blood pressure.
Title: Blood pressure
Post by: Seany on 25/04/2007 20:52:08
Speaking as a young-un, I hopefully have a normal blood pressure [;)]
Title: Blood pressure
Post by: DoctorBeaver on 26/04/2007 08:56:00
My blood pressure is a tad under normal and has been for as long as I can remember.
Title: Blood pressure
Post by: paul.fr on 26/04/2007 14:32:40
Paul - My doctors say I have low blood pressure. 

I just took it and it was 117/65, ...................

Thanks all, but what do the numers 117/65 represent?
Title: Blood pressure
Post by: RD on 26/04/2007 15:35:56
The numbers are the pressure in millimeters of mercury (mmHg)
Title: Blood pressure
Post by: rosy on 26/04/2007 15:43:09
The upper number is the pressure of blood on its way into your arm (in the artery) and the lower is the pressure on its way out (back through the veins).
If you have a cuff on your arm between the two pressures, apparently, blood can be forced down your arm but not get out... not something you'd want for any length of time...
A pretty crude and possibly over simplified view I gained whilst my arm was being used to illustrate a kids talk... I may not have been paying full attention, but I think that's what was said.
Title: Blood pressure
Post by: elegantlywasted on 26/04/2007 15:43:18
Okay, the top number is the systolic pressure, and the bottom is the diastolic. Normal resting BP is 120/80. The systolic pressure is measured when the blood leaves the heart, and the diastolic is when the ventricles are relaxed.

Below is an image from the very expensive Bio textbook I bought and used twice. Its a rather large picture but thats the only way you can read it.
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi154.photobucket.com%2Falbums%2Fs252%2Felegantlywasted_2007%2FBP.jpg&hash=50efade4e66a1a24b688abf851ff1805)
Title: Blood pressure
Post by: that mad man on 26/04/2007 17:18:46
I have a bit of low blood pressure that can sometimes make me dizzy if I bend down and get up too quick.


If you have a cuff on your arm between the two pressures, apparently, blood can be forced down your arm but not get out... not something you'd want for any length of time...


Its also very painful when the cuff is released if the circulation has stopped for a while, "pins and needles" we call it.
Not sure what causes the pain though.

Bee
Title: Blood pressure
Post by: rosy on 26/04/2007 17:37:17

Quote
Its also very painful when the cuff is released if the circulation has stopped for a while, "pins and needles" we call it.
Not sure what causes the pain though.
It's because the nerve cells in the cut-off area stop working when they don't get any oxygen/sugar (the biggest ones stop working first), that's why the arm goes numb and won't move. Don't know why it hurts when they start working again though.
Title: Blood pressure
Post by: Karen W. on 28/04/2007 03:50:54
Mine has been running 110 over 78 and 80 for the past two weeks or so..

For a few months it was a constant 114 over 80.. I am not sure why it has droppedbut it has.. I feel fine though I can't tell the difference really!