“Blood work after donating blood?”

Donating blood should not affect your annual physical labs. The body compensates very quickly and and your hemoglobin level should go back to where it was before you donated. Just let your doctor know that you donated. If your hemoglobin is a little lower than your usual, you should retest in about a month or so.

Dr. Lamiaa Tolba, PA-C, DMSc

Good morning. I am happy to answer your question. Blood cells typically get renewed after 3 months. It means that if you donate/lose 1unit of red blood cells it will take your body about 3 months to replace the cells you lost provided your body has enough ingredients required by your bone marrow to do that. Thus within 3months from the time you donate/lose 1 unit of blood, your hemoglobin will be lower by about 1 point.

First of all, thank you for donating blood as we are experiencing a national shortage of blood products due to the COVID epidemic. Donating blood does not affect most studies. It can affect testing for anemia, certain vitamins, and bone marrow functions. Usually donating one pint of blood may decrease your blood count by up to 10 to 11%. It can decrease your body’s iron levels by 220 to 250 mg. It may lower your measured vitamins temporarily. It can also increase levels of the tests determining your bone marrow function. It can take up to 16 weeks for most of these tests to return to what you were before the donation. If your doctor is not checking for these, the blood donation should not affect any other levels.