# Can donating blood reduce high blood pressure? **URL:** \ **Category:** Factual Questions\ **Created:** [November 20, 2002, 3:39pm UTC](https://boards.straightdope.com/t/can-donating-blood-reduce-high-blood-pressure/137743 "2002-11-20T15:39:51Z")\ **Posts on this page:** 7\ **Page:** 2
**Author:** ![Demo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/demo/32/8472_2.png) [@Demo](https://boards.straightdope.com/u/Demo)\ **Post date:** [November 26, 2002, 3:54pm UTC](https://boards.straightdope.com/t/can-donating-blood-reduce-high-blood-pressure/137743/21 "2002-11-26T15:54:46Z")
> [@](#): > > \*Originally posted by istara \* > \*\*Can someone here please give me the one-line idiot’s guide to the difference between systolic and diastolic? \*\* Systolic pressure is pressure during a heart contraction. Diastolic is pressure during relaxation. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [November 26, 2002, 7:08pm UTC](https://boards.straightdope.com/t/can-donating-blood-reduce-high-blood-pressure/137743/22 "2002-11-26T19:08:46Z")
> [@](#): > > \*Originally posted by partly\_warmer \* > \*\*A quantity of perfumed blessings to your enviorns, Qadgop. I’ve been waiting, indefinitely stalled, to hear such a clear statement of the current recommended practice about this, and hearing little but “Be Good”. Nice to hear that other people can’t figure it out, either. Ta. \*\* I should add that _many_ hypertensive patients do all the correct things and still require anywhere from one to four different medications to correct their blood pressure. I did not mean to imply that lifestyle modification would automatically make all the difference. ---
**Author:** ![reprise](https://avatars.discourse-cdn.com/v4/letter/r/ea666f/32.png) [@reprise](https://boards.straightdope.com/u/reprise)\ **Post date:** [November 26, 2002, 7:27pm UTC](https://boards.straightdope.com/t/can-donating-blood-reduce-high-blood-pressure/137743/23 "2002-11-26T19:27:29Z")
I’m not even going to try to attempt a technical explanation for this - I’ll leave that to the physicians in residence - but I have chronically **low** blood pressure. I’m not unhealthy because of it, I just have a tendency to faint in hot weather if I don’t drink fluids by the clock. Twice in my life I have had accidents which involve massive bleeding. Because of the adrenaline the body pumps when you are losing large volumes of blood, my blood pressure actually ROSE while I was losing significant amounts of blood. Had it not been for the ambos who were aware of my chronic hypotension, I would probably have died - there wasn’t a single doctor in the ER who realised that I was in trouble once my BP reached 120/80 (that is BIGTIME high for me, and definitely a sign of adrenaline in response to massive blood loss). Your blood pressure most certainly CAN go down when you donate blood, but for most people the difference in blood pressure is negligible. I’ve learned to live with hot weather and the inevitable hypovolemic episodes it brings. I really can’t imagine that anyone would WANT to feel the way I feel when my blood pressure does the sudden plummet, let alone allow someone to stick a huge gauge needle in their arm in order to induce that feeling. I know that QtM is probably going to ask - the worst hypovolemic episode I’ve had was 90/42, and I was just fine once I had a drink of fluids. Summer and me just don’t agree with each other. ---
**Author:** ![sqweels](https://avatars.discourse-cdn.com/v4/letter/s/f19dbf/32.png) [@sqweels](https://boards.straightdope.com/u/sqweels)\ **Post date:** [November 26, 2002, 8:23pm UTC](https://boards.straightdope.com/t/can-donating-blood-reduce-high-blood-pressure/137743/24 "2002-11-26T20:23:07Z")
Thanx for the responses. Naturally, the conditions keeping my BP high now would bring it right back up, but I was thinking that if I’m gonna start a regimen designed to lower it, a little bloodletting might be a good way to get the ball rolling. ---
**Author:** ![Spoke](https://avatars.discourse-cdn.com/v4/letter/s/a88e57/32.png) [@Spoke](https://boards.straightdope.com/u/Spoke)\ **Post date:** [November 26, 2002, 9:15pm UTC](https://boards.straightdope.com/t/can-donating-blood-reduce-high-blood-pressure/137743/25 "2002-11-26T21:15:01Z")
Would it be a leap to speculate that we perhaps evolved to bleed a lot more than we actually do these days? (Our cushy office jobs can’t match the African savannah for blooodletting incidents.) ---
**Author:** ![Spoke](https://avatars.discourse-cdn.com/v4/letter/s/a88e57/32.png) [@Spoke](https://boards.straightdope.com/u/Spoke)\ **Post date:** [November 26, 2002, 9:17pm UTC](https://boards.straightdope.com/t/can-donating-blood-reduce-high-blood-pressure/137743/26 "2002-11-26T21:17:20Z")
(Paper cuts notwithstanding.) ---
**Author:** ![reprise](https://avatars.discourse-cdn.com/v4/letter/r/ea666f/32.png) [@reprise](https://boards.straightdope.com/u/reprise)\ **Post date:** [November 26, 2002, 9:56pm UTC](https://boards.straightdope.com/t/can-donating-blood-reduce-high-blood-pressure/137743/27 "2002-11-26T21:56:54Z")
I don’t know about the rules in the US, but here the Red Cross won’t accept a donation unless it’s been 60 days or more since you last donated. There are certain medical conditions which require regular blood-letting, but if you had one of them you would most certainly know about it. If you want to donate blood - cool; do it because it’s something nice you can do for this world. Just don’t do it hoping that it will have a significant impact on your BP, because that impact will be very short-lived. [Previous page](https://boards.straightdope.com/t/can-donating-blood-reduce-high-blood-pressure/137743.md?page=1)