Blood donation
Apr. 17th, 2026 08:24 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
johnckirkToday I made my 25th blood donation, which was also my first platelet donation.
I made my first blood donation when I was 18, at the university's student union. I continued with this for a while after graduation, but then got out of the habit, until I resumed donations a couple of years ago. There have been some changes to the eligibility requirements, so if you've been turned away in the past then you might be allowed to donate now.
In particular, this affects men who've had sex with other men:
* Prior to 2011, there was a lifetime deferral (i.e. a blanket ban).
* In 2011, this was changed to a 12 month deferral (i.e. you had to wait 1 year after sex before donating blood).
* In 2017, this was reduced to a 3 month deferral.
* In 2020, the waiting period was eliminated, as long as you've only had 1 partner in the past 3 months. (E.g. you could have sex with that partner the day before donation.)
Originally, I donated "whole blood". That's the traditional approach, where they take about a pint of blood out of you. ("That's very nearly an armful!" as Hancock once said.) This is then split up into pieces, e.g. red blood cells, white blood cells, plasma, and platelets.
Platelet donation is a bit different, because it uses apheresis. Basically, the blood gets taken out, then the platelets are extracted, and the rest of the blood is put back in. This means that they can take more platelets during a donation, because my overall volume of blood will stay about the same. So, looking at the reward scheme, I get 1 credit for each whole blood donation but 2 or 3 credits for each platelet donation. (Although this was my 25th donation, I now have 26 credits.)
According to a campaign from 2021:
"Platelets are cells within the blood that are crucial for patients with blood cancers, such as leukaemia, and a range of illnesses and accidents. [..] Nearly 70% of platelet donations are used to help people with cancer."
If you want to donate platelets, you need to register your interest before a "normal" donation. They'll then take an extra tube of blood to test. Aside from that, you also need to have fairly large veins for platelet donation. When I donated in November, the nurse on duty looked at my left arm, but they said that I should stick to whole blood donation. At the time, I thought that this was just informal advice, but I never heard back with the test results, so I realised that the process hadn't gone any further.
At my next donation, in March, I tried again. The nurse looked at my left arm, and agreed that those veins aren't good enough. However, they then looked at my right arm and said that those veins are fine, so that's what I used today.
Related to that, I think that platelet donation used to involve both arms (i.e. take blood out of one and put it back into the other), but my donation was done through a single arm. That's convenient, because it leaves the other arm free. I was plugged into the machine for about an hour, and I was able to use my free hand to read a book on my phone. They put a warming pad under my right arm (with a tube attached), presumably to help my circulation.
Each time I give blood, they start by testing my haemoglobin levels. This involves taking a small amount of blood from my finger and dropping it into a tube of liquid (a copper sulphate solution). If the blood sinks to the bottom, that means that there's enough iron in it to make it heavy.
I noticed recently that there were 2 tubes on the desk, 1 blue and 1 green. I asked the nurse on duty, and they explained that there are different limits for men and women. I'm not sure whether that's a recent change, or just something that I hadn't paid attention to before.
Normally, my blood sinks like a stone. However, when they tried today, the blood went down a couple of cm in the tube, then floated there for a few seconds before slowly drifting down to the bottom of the tube. They tried again, and the same thing happened; in fact, the blood seemed to go up slightly before it sank!
However, this wasn't a deal breaker, because they have a gadget to do a more accurate test. This is a HemoCue, which was introduced in 2018 but today was the first time I've needed to use it. They took blood from my left arm (since I'd be donating from my right arm), and my haemoglobin (Hb) was 147 g/L. The minimum amount is 135 g/L for men (or 125 g/L for women), so I was comfortably over that. That suggests that there might have been a problem with the liquid in the tube; the way my blood paused reminded me of a thermocline (where you can have warm water at the top of a lake and cold water below it). However, I'll leave other people to investigate that.
I became a vegetarian when I was 18, and I heard lots of comments about anaemia. So, a fringe benefit of blood donation is that I know my iron levels are fine, i.e. I don't need to eat meat to be healthy.
I made my first blood donation when I was 18, at the university's student union. I continued with this for a while after graduation, but then got out of the habit, until I resumed donations a couple of years ago. There have been some changes to the eligibility requirements, so if you've been turned away in the past then you might be allowed to donate now.
In particular, this affects men who've had sex with other men:
* Prior to 2011, there was a lifetime deferral (i.e. a blanket ban).
* In 2011, this was changed to a 12 month deferral (i.e. you had to wait 1 year after sex before donating blood).
* In 2017, this was reduced to a 3 month deferral.
* In 2020, the waiting period was eliminated, as long as you've only had 1 partner in the past 3 months. (E.g. you could have sex with that partner the day before donation.)
Originally, I donated "whole blood". That's the traditional approach, where they take about a pint of blood out of you. ("That's very nearly an armful!" as Hancock once said.) This is then split up into pieces, e.g. red blood cells, white blood cells, plasma, and platelets.
Platelet donation is a bit different, because it uses apheresis. Basically, the blood gets taken out, then the platelets are extracted, and the rest of the blood is put back in. This means that they can take more platelets during a donation, because my overall volume of blood will stay about the same. So, looking at the reward scheme, I get 1 credit for each whole blood donation but 2 or 3 credits for each platelet donation. (Although this was my 25th donation, I now have 26 credits.)
According to a campaign from 2021:
"Platelets are cells within the blood that are crucial for patients with blood cancers, such as leukaemia, and a range of illnesses and accidents. [..] Nearly 70% of platelet donations are used to help people with cancer."
If you want to donate platelets, you need to register your interest before a "normal" donation. They'll then take an extra tube of blood to test. Aside from that, you also need to have fairly large veins for platelet donation. When I donated in November, the nurse on duty looked at my left arm, but they said that I should stick to whole blood donation. At the time, I thought that this was just informal advice, but I never heard back with the test results, so I realised that the process hadn't gone any further.
At my next donation, in March, I tried again. The nurse looked at my left arm, and agreed that those veins aren't good enough. However, they then looked at my right arm and said that those veins are fine, so that's what I used today.
Related to that, I think that platelet donation used to involve both arms (i.e. take blood out of one and put it back into the other), but my donation was done through a single arm. That's convenient, because it leaves the other arm free. I was plugged into the machine for about an hour, and I was able to use my free hand to read a book on my phone. They put a warming pad under my right arm (with a tube attached), presumably to help my circulation.
Each time I give blood, they start by testing my haemoglobin levels. This involves taking a small amount of blood from my finger and dropping it into a tube of liquid (a copper sulphate solution). If the blood sinks to the bottom, that means that there's enough iron in it to make it heavy.
I noticed recently that there were 2 tubes on the desk, 1 blue and 1 green. I asked the nurse on duty, and they explained that there are different limits for men and women. I'm not sure whether that's a recent change, or just something that I hadn't paid attention to before.
Normally, my blood sinks like a stone. However, when they tried today, the blood went down a couple of cm in the tube, then floated there for a few seconds before slowly drifting down to the bottom of the tube. They tried again, and the same thing happened; in fact, the blood seemed to go up slightly before it sank!
However, this wasn't a deal breaker, because they have a gadget to do a more accurate test. This is a HemoCue, which was introduced in 2018 but today was the first time I've needed to use it. They took blood from my left arm (since I'd be donating from my right arm), and my haemoglobin (Hb) was 147 g/L. The minimum amount is 135 g/L for men (or 125 g/L for women), so I was comfortably over that. That suggests that there might have been a problem with the liquid in the tube; the way my blood paused reminded me of a thermocline (where you can have warm water at the top of a lake and cold water below it). However, I'll leave other people to investigate that.
I became a vegetarian when I was 18, and I heard lots of comments about anaemia. So, a fringe benefit of blood donation is that I know my iron levels are fine, i.e. I don't need to eat meat to be healthy.
