How much blood is taken at the time of donation? How soon
does the body make good this loss?
Only 350 ml of blood is taken at the time of donation. An
average person has 5-6 litres of blood in the body.
In terms of volume the loss is corrected in 24-48 hours by
the body. The red cell count is corrected in about 56 days.
How long does the process of donation take?
The actual bleeding time is about 5-6 minutes. There will be
a medical check up before this and you will be advised some rest ( for 5-10
minutes) and given some refreshment after donation. The whole process takes
about 30 minutes.
How often can one donate blood?
The minimum time advised between two donations is 3 months.
This gap helps blood regain the normal haemoglobin count.
Are there any hazards in blood donation? What are the
precautions that need to be taken?
Your health will not suffer because of the blood you have
donated. In fact, the bone marrow is stimulated to produce new cells.
However if conditions are not hygienic, you may be exposed to
infection.
Precaution: Be sure that disposable needles are used for
bleeding.
What happens to the blood that is donated?
The blood is screened for the following diseases/infections:
- HIV
- Hepatitis B & C
- Syphilis
- Malaria
The blood is grouped and stored either as whole blood or as
components like Packed red blood cells, plasma or platelets. This is then sent
on demand to hospitals.
How is Blood Grouped?
Blood is composed of cells suspended in a liquid.
The liquid portion is the plasma, from which therapeutic fractions and
derivatives are made.
Suspended in the plasma are three types of cells:
Red cells: These carry Oxygen
White cells: These fight infection
Platelets: These stop wounds bleeding
The most common type of grouping is the ABO grouping. Red
Blood Cells have a protein coat on their surface which distinguishes them.
According to this blood is divided into four groups:
A (A protein is present), B (B protein is present),AB (AB
protein is present)and O ( No protein is present).
There are subtypes under this grouping ( listed as A1, A2,
A1B or A2B…) some of which are quite rare.
Apart from this there is another protein which plays an
important part in the grouping of blood. This is called the Rh factor. If this
is present, the particular blood type is called positive. If it is absent, it is
called negative. Thus we have the following broad categories:
A1 Negative
A1 Positive
A1B Negative
A1B Positive
A2 Negative
A2 Positive
A2B Negative
A2B Positive
B Negative
B Positive
O Negative
O Positive
( Information Courtesy: Indian Red Cross Society, Tamil
Nadu Branch. )
