I keep getting deferred when I try to donate whole blood, due to a low hematocrit level. I’ve tried the usual methods to increase my count and I still fail or barely pass.
The Red Cross nurse didn’t know the answer to this question: After ruling out the usual causes of a low hematocrit, can drinking copious amounts of water lower the count?
Generally not. In otherwise healthy individuals, the body works to keep the plasma concentration about the same, by regulating urine output. Dehydration and rehydration can make for brief fluctuations in the hematocrit, but that is about it unless disease is present.
QtM, MD
I donate plasma and although they say water doesn’t matter with hematacrit it does with me! They told me that mines was low due to iron and gave me a list to bring it up but I have learned through trial and error that drinking too much water is the cause I get turned away. As a result I try not to drink too much water the day before I know i’m going to donate. After my screening I drink plenty of water or juice and I am fine. Drinking lots of fluids after in a must after this. I haven’t got turned away since I “dry out” the day before. Hope this helps.