My husband had very elevated hemoglobin levels about 6 months post-transplant and ended up having to have a phlebotomy (like giving blood was not able to donate it). He also was placed on a medication, sorry I am not able to remember the name of the med right now. He has not had to undergo a phlebotomy again and the meds seem to keep the levels at bay. Before all this, I did not know you could have too much blood! So much to learn.