The low blood volume in the body is called hypovolemia. It is the decrease of plasma in blood. The causes of hypovolemia can be use of some drugs, an injury, vomiting, frequent blood donation, sweating, dehydration and use of alcohol. The minor blood deficiency needs no treatment. Only apple juice ad solid proteins can be helpful. You are having 3 pint short in blood. If you are not feeling anemic, then take solid proteins and apple juice otherwise get medical attention.