I have been donating blood on a regular basis since I was 18 - as in 40 years, wow. I did have some gaps but for the most part I try to donate at least 4 times a year.

I have always struggled with low Iron but the last ten years I have been pretty good, until this year. I should preface that I haven't had a blood panel done by my doctor but will do that this next month.

So went to give blood on January and my hematocrit level was to low for their standards. Then I was successful in April but feel pretty puny for about 48 hours. Yesterday I donated again. His first check of my hematocrit was low but then he tried again with the other hand and it was well within the acceptable range. But again, I now have very little energy despite drinking a ton of water before giving and throughout yesterday. Fell asleep at 8 pm last night.

Is it age? Anybody else go through this? My blood pressure is always on the low side - but that has been that way my entire life. Resting heart rate is typically somewhere in the 60's which isn't low.
And I should note I am not underweight (nor overweight)
Just curious if anyone else goes through this. Hoping to go out on the bike this morning, will see if I can make it over the hill