Can blood donation cause any harm to the donor? I have been told so, but cannot find any references supporting this claim. I have also learned that our body will replace the lost fluids within 24 hours and the RBCs within weeks. Can blood donation still cause health issues for our body?

This is not a personal medication question, and I mainly want to know how the body responds to blood loss and what mechanisms that monitor the altered levels of blood volume? To me, it would also be unethical by medical doctors to withhold the possible risks of blood donation to prospective donors, but it might also be seen as unethical to discourage a person willing to donate blood from doing so, so there might be a conflict of interest here.

  • 3
    $\begingroup$ If this is not a personal medical question, you should remove all references to yourself. Also, medical ethics specifically prohibits hiding information from patients. $\endgroup$
    – canadianer
    Mar 27, 2015 at 7:45
  • $\begingroup$ @canadianer:I have removed $\endgroup$ Mar 27, 2015 at 8:26
  • $\begingroup$ I don't understand your question. Do you want to know if blood donations are harmful for the donor? $\endgroup$
    – Chris
    Mar 27, 2015 at 8:58
  • $\begingroup$ @Chris: Yes thats what I am looking for ! $\endgroup$ Mar 27, 2015 at 9:03
  • $\begingroup$ Tried to clarify your question. Feel free to roll-back if you disagree. $\endgroup$ Mar 27, 2015 at 9:04

1 Answer 1


My answer below directly (and solely) addresses what I think is the main gist of the question: Are there any adverse effects on one's physiology as a direct result of donating blood?

Blood donation, at the amounts typically taken (200~500mls), will not harm you. A healthy human being produces approximately 100,000,000,000 (one hundred billion) NEW hematopoietic cells DAILY to replenish short-lived blood cells and platelets. All of these ultimately derive from the hematopoietic stem cells residing in the bone marrow within one's long bones.

As you can appreciate, with such a huge amount of turnover daily, the body is constantly churning out new blood cells. Thus, any depletion in blood cells one will experience as a result of blood donation is a fraction of what will be lost normally in daily homeostasis anyway and thus will not affect a healthy individual.

And then there are the knock-on benefits suggested by epidemiological studies, some of which are alluded in this layman article: http://news.health.com/2014/06/13/4-unexpected-benefits-of-donating-blood/

[source: I'm a hematologist]

  • $\begingroup$ How much amount of blood loss is considered as fatal ? $\endgroup$ Mar 30, 2015 at 11:03
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    $\begingroup$ If you lose > 40% of blood volume (~2.5 L for a 75kg healthy adult male), it is most likely fatal. However, one will probably start to feel the effects (classed as hypvolemia) after >15% blood loss. As you can see, even at maximal amounts of blood donated, it is a tiny fraction of total blood volume and certainly not going to be fatal. You seem to be excessively concerned about a safe procedure that has been routinely done for over 5 decades. The biggest harm is not from donating, but from NOT donating! $\endgroup$ Mar 31, 2015 at 1:29
  • $\begingroup$ Your answer and comment seems awesome and I am glad that you are worried about by excessive concerns :) $\endgroup$ Mar 31, 2015 at 3:03
  • $\begingroup$ @Cantona Collar What on earth? You can start feeling the effects of blood loss (hypovolemia) after 15% blood loss? At 2.5L for a healthy adult male 15% is 375ml and you say they take 200-500mls. Seems to me from these numbers they take so much blood it approaches the quantity of blood loss which is approaching hypovolemia already. $\endgroup$
    – Zebrafish
    Feb 26, 2018 at 16:05
  • $\begingroup$ @Zebrafish, I think you need to re-read what I wrote before typing. The total volume of blood in an average healthy human is ~5L (webcitation.org/mainframe.php) $\endgroup$ Jul 11, 2018 at 5:07

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