Sweating, nausea, fainting, stomach pain after donating blood. Reason?
Patient: I just gave blood.  I was fine during and after and stayed at the canteena for a soda.  I had to go to the wireless phone store and ended up being an hour on my feet.  I began sweating terribly, felt nauseous, and almost fainted.  After sitting for a while the dizziness passed but I double over with stomach pain.  Can this be related to the blood donation?  If so, how come?  I have given blood many times and never had such a reaction.Thank you for your insight. Doctor: hi..you have donated your blood.. congratulations..after that you had fainting episode after long standing, it could be due to postural hypotension and pain abdomen due to drinking soda, might be due to gastric irritation..don't worry, you need to take some rest, take lot of fluids, oral rehydration solution... you will be all right..