If I donate a pint of blood to the Red Cross, how many red blood cells will Iose (percent)?

Question

Actually I want to lose some because my hemoglobin count is at 19 and my doctor says it should be 16 or below.

Answer 1

I agree.  The problem is not that you have high a red blood cell count.  The problem is that it's an indicator of something you should be worried about.

Otherwise I'd like to point out the obvious.  In the short term there's no effect on your count because you're not just losing blood cells when you donate blood, but all the components that make up blood fluid proportional to their amounts in your body.  When you rehydrate later your blood will get a little watered down.  However that's a temporary effect, since, as was written before, your body regulates your blood cell count.

Answer 2

An avg size male has 4.7 to 6.1 million/uL, and has 3 L of blood.

Some increases of high RBC can be:

Living at a high altitude

Smoking

strenous exercise

Dehydration, such as from severe diarrhea or excessive sweating

Exposure to carbon monoxide

Anabolic steroid use

Your body has controls that regulate the concentration of RBCs.  .  You should contact your doctor to determine why your RBC count is high.  Only he can tell you why, and you should know if there is a concern or not.  The increase is a result of some factor, and you cannot drain yourself of blood to fix it.