How much blood can a person donate before it can affect their health?

Answer 1

Studies have indicated that volunteer whole blood donors begin experiencing adverse reactions (weakness, nausea, vomiting, syncope, etc) when blood loss exceeds 15% of total blood volume. As such, FDA recommendations, listed below, are in place to assure that less than 15% is collected from volunteer blood donors.

Current FDA guidelines allow a maximum of 10.5 ml/kilogram body weight of whole blood to be collected every eight weeks. The majority of blood collection facilities use 500 ml whole blood bags, with an additional 50 ml (10%) allowed to be drawn for mandated screening tests. This volume equates with a lower body weight for blood donation of 110 lbs or more (with acceptable hematocrit/hemoglobin levels).

Double red cell donation by apheresis technology may collect 500-550 ml of red cells at a single donation IF the donor meets body mass and hematocrit eligibility criteria. Double red cell donors must wait 112 days before their next blood donation attempt (any type).

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