An adult male or female carries about 5 litres of blood in the blood circulation system. This volume is less in children by about a litre (-0.8 litres). During blood donation, what is removed is less than 10% of the blood volume. About 500 ml of blood is removed from the donor’s vein. Within 24 hours of blood donation, this volume is replaced. The donor is usually advised to increase his fluid intake. Although haemoglobin concentration falls following a blood donation, but within 2 months haemoglobin returns to its previous value (pre-donation status) even without taking drugs. In some centres, milk or stout or ferrous tablets are prescribed for the donor. They stimulate the bone marrow to produce more blood in order to improve the haemoglobin concentration. Good food containing protein (eggs, milk etc.) vitamins and minerals (fruits and vegetables) help to stimulate the marrow to produce blood. A healthy individual can donate blood every three months if he maintains good nutritional status.
The age group allowed for blood donation is 16 to 65 years in developed countries such as Europe, America, USSR; and 18-60 years in developing countries (Nigeria). The difference in age group lies in the nutritional state of communities in developing countries, where feeding is not as good as that in developed countries. Women and men can donate equal volume of blood. Menstruation is not a risk factor. Pregnancy and childbirth are risk factors. Blood volume varies with age as it has already been mentioned. The blood volume in a child is not the same as that in an adult. Differences have been found in blood volume of individuals within the same age group and their weights. A positive relationship exists between body size and blood volume of children although the differences is not much.
As a rule any adult who is in good health and has not had any serious illness is a suitable donor of blood. There are regulations designed to protect the donor and the recipient. A blood donor may be disqualified from donating blood if have the following conditions:
1. Communicable diseases such as hepatitis, malaria. HIV/AIDS, syphilis, bacterial infections, trypanosomiasis and few others.
2. Recent injections of vaccines. A donor who has recently been vaccinated should not donate blood because the blood should be at least one month from the day of vaccination.
3. Donors who suffer from severe allergy may transfer their sensitivity to the recipient although for a short period. Hence they should not donate.
4. Presence of inherited red cell abnormality such as sickle cell disease, thalasaemina, G-6-PD deficiency.
5. In pregnancy state, blood donation can cause iron deficiency or anaemia.
6. Children are not allowed to donate blood.
7. If the donor has been bled twice before within a year.
8. Anaemia. It is advisable to perform a test on all blood donors to make sure that they are not anaemic. This is achieved by taking a drop of blood from the donor and allowing falling into a situation of copper sulphate to determine its specific gravity. The drop either sinks or floats. Donors who are confirmed anaemic should not donate blood.
9. Epilepsy.
10. Kidney diseases
11. Old age
12. Blood diseases such as leukaemia.
Healthy males and females can donate a pint of blood once twice yearly without any side effects,
Provided such donors eat well. When the interval between donations is shorter than the six months
the donor faces the risk of anaemia. Every donor must be screened and certified fit for blood
donation in order to promote his health and to protect the recipient from acquiring illness following
blood transfusion. A health person donates blood to a recipient. The purpose of blood donations is
Blood transfusion.
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