What you need to know before you donate blood
Health & Science
By
Rose Mukonyo
| Jul 22, 2024
According to Gladys Omwenga, a Medical Laboratory Technologist at Mama Lucy Hospital Blood Donation Centre, some basic requirements are considered before a blood donation.
"A person can donate blood if they are 16 years to 65 with a minimum weight of 50 kilogrammes and a maximum weight of 120 kilogrammes but we do not encourage one to donate for the first time if they are 65 years old," she says.
They should also be of good health, not on any medication or underlying conditions such as asthma, hypertension or diabetes, not under any drug use, and no recent vaccinations or surgeries.
Omwenga says when someone is preparing for a blood donation, they need to have eaten at least 6 hours prior, taken half a litre of water before donation and should not have taken alcohol within the previous 24 hours.
She says that amount of water is recommended because a similar amount of blood is drawn from the body and may leave one feeling dehydrated, which is why a person may feel dizzy or like they might faint after a donation. It is the reason we give a soda because it has water and glucose," she explains.
When one gets to the blood donation centre, some tests are done, such as blood pressure and haemoglobin levels (Hb level). The normal Hb level for males is 14 to 18 grammes per decilitre (g/dl) and that for females is 12 to 16 g/dl.
Additionally, a person fills out a questionnaire for risk assessment as some people may be considered high risk due to their professions or sexual behaviour and may not be suitable donors.
She adds that certain groups of people cannot be allowed to donate blood, including pregnant and lactating women, people on medications such as for epilepsy, diabetes and sickle cells, people on drugs like cocaine and marijuana, and people with bleeding conditions or women with irregular or prolonged menstrual periods.
Omwenga explains that blood donations benefit a blood donor by reducing the levels of iron cells in the body, saying that having excess iron may contribute to the growth of cancer cells.
"When someone has anaemia, they are given iron supplements, but when you have too much iron in your blood, it is not beneficial because those cells will expire after 120 days and remain in your blood system as waste," she says.
She says giving blood also stabilises cholesterol levels and stimulates the immune system by producing fresh cells. She urges people to donate blood, explaining that men can do so every three months while women can donate after four months.