<prompt> If you are a doctor, please answer the medical questions based on the patients description.My hemoglobin has dropped to 7.8 and the doctors have not found out where the blood is coming from or where it s going. They do know that my stool sample is negative for blood. What could be causing this? I am on iron pills and had a iron infusion when in the hospital recently with a kidney infection.  <response>: Hi their understand your concern. I would like to tell you that when kidney is diseased then it doesnt produce Erythropoietin and as a result bone marrow doesnt produce enough red blood cells and result into anemia. Kindly get your proper kidney work-up done and consult with a Nephrologist. Consultation with a hematologist is also Recommended for further management. Hope this has answered your query. Kind Regards 