Blood mainly contains a fluid called plasma which has three types of cells – red blood cells or RBCs, white blood cells or WBCs and platelets.

Usually, any person within the age group of 18–60 years with a minimum body weight of 45 kg, and having a minimum haemoglobin content of 12 g/dL is eligible to donate. However, all countries have criteria for blood donation in their respective countries.

The procedure is done by skilled, specially trained technicians and takes three to eight minutes. However, from start to finish (filling form, postdonation rest etc.) the entire process should take around 30 minutes.

Whole blood can be stored for up to 35 days, when kept in CPDA anticoagulant solution and refrigerated at 2–4 °C.

Yes. All blood units are tested for HIV/AIDS, hepatitis B, hepatitis C, malaria and antibodies to syphilis. Only those units of blood are transfused which are free from these infectious markers.

Every individual has two types of blood groups. The first is called the ABO - grouping and the second type is called Rh - grouping. In the ABO - group there are four categories namely A Group, B Group, O Group and AB Group. In the Rh - Group either the individual is Rh-positive, or Rh-negative. Rh is a factor called as Rhesus factor that has come to us from Rhesus monkeys. Thus each and very human being will fall in one of the following groups. A positive or A negative B positive or B negative O positive or O negative AB positive or AB negative There are also some sub groups as well as a few other classifications.

For all practical and routine purposes, it is ideal to transfuse to the patient the same group of blood which he belongs to. It is only under very dire emergency that we take O group as universal donor and AB groups as universal recipient. Under no circumstances O group can get any other blood except O. Similarly A group patient cannot be given B group blood and vice versa.

This is due to the reason that, the blood of A Group people contains anti - B antibodies. In B group people there are anti - An antibodies. If we give A group blood to a B group patient, it is bound to be incompatible and will result in serious consequences.

A patient with Rh-negative blood cannot be given Rh-positive blood as the antigen-antibody REACTIONS WILL RESULT IN SEVERE consequences. In cases where a woman has Rh negative and her husband has Rh positive, the first child with Rh positive may be normal. But subsequently the woman may not conceive or may have repeated abortions. There may be intra uterine fetal death. If the child born is alive, it will suffer from a fatal disease called "Erythroblastosis Foetalis". Now mothers can be given an injection of anti-D within 24 hours of the delivery of a Rh-positive child and thus protect the next baby from this catastrophe.

Blood is collected in plastic bags which contain a watery fluid which prevents blood from getting coagulated. On an average we draw about 450 ml. of blood from a person, depending on the weight of the donor. This blood, plus the amount of anti coagulant present in the bottle or bag, is known as one unit of blood.

Scientists have tried a lot but so far they are not successful. Only the blood of a human being can be transfused to a human patient.

Whole blood can be stored up to 35 days, when kept in CPDA anti coagulant solution and refrigerated at 2 - 4 deg C. But the demand is so great that blood hardly ever remains in storage for so long and is used much before expiry.

Yes! Now with technical advancements, we can make components of blood and store them. For example, plasma can be separated from whole blood and stored up to one year in frozen state at -80 deg C temperature or below. This is called Fresh Frozen Plasma. Similarly there are other components like Platelet Rich Plasma; Platelet Concentrate (can be stored as a life saving measure upto 5 days now at 22- 24 degrees C in a platelet incubator and agitator); Cryoprecipitate (which is very useful in treating bleeding disorders due to the deficiency of factor VIII and IX); Factor VIII and IX; Albumin, Globulin and many others. In most progressive blood banks more than 85 % of the blood collected is converted into components and stored. This is because many patients do not require whole blood. For example, a patient whose haemoglobin is low and is therefore anemic, may just require Packed Cells i.e. only red cells; a patient with burns may need more of plasma than cells; a patient with hemophilia may require only Factor VIII. Now with the advent of Cell-separators we can directly draw a particular component from the donor, while rest of the blood constituents go back to the donor.

The following symptoms may occur after only a few ml. of blood have been given:
1. Patient complains of shivering, restlessness, nausea, and vomiting. There is precardial and lumbar pain.
2. Cold, clammy skin with cyanosis.
3. Pulse rate increases, respiratory rate increases. Temperature increases to 38 to 40 deg C. [101 to 105 F].
4. Blood pressure falls and patient passes into a state of shock.
5. Haemoglobinaemia, haemoglobinurea (urine turns red); oliguria (urine becomes scanty or the urinary output is reduced) and anuria (total output of urine becomes 200 ml. a day)
6. Jaundice appears after a few hours and in some cases anuria persists and uremia develops. This may lead to death.

There are three types of blood donors: -
(1) PROFESSIONAL DONORS - They sell their blood, which is of very poor quality and can transmit very dangerous diseases to the recipient. It is illegal to take blood from any professional donor.
(2) REPLACEMENT DONATION - Healthy relatives and friends of the patient give their blood, of any group, to the blood bank. In exchange, the required number of units in the required blood group is given.
(3) VOLUNTARY DONATION- Here a donor donates blood voluntarily. The blood can be used for any patient even without divulging the identity of the donor. This is the best type of blood donation where a motivated human being gives blood in an act of selfless service.

Any person within the age group of 18 - 55 years with a body weight as minimum 45 kgs, and having haemoglobin content as minimum 12.5 gm%.

The donor should eat at regular mealtimes and drink plenty of fluids.

The procedure is done by skilled, specially trained technicians and takes three to eight minutes. However, from start to finish (filling form, post donation rest etc) the entire process should take upwards of 35 minutes.

There may be a little sting when the needle is inserted, but there should be no pain during the donation.

Absolutely not, rather a donor after having given blood voluntarily gets a feeling of great pleasure, peace and bliss. Soon, within a period of 24 - 48 hours, the same amount of new blood gets formed in the body, which helps the donor in many ways. His own body resistance improves, the circulation improves, and he himself feels healthier than before

Of course! Routine work is absolutely fine after the initial rest. Rigorous physical work should be avoided for a few hours.

After resting for a while a donor is given some liquid (fluid) to take. It may be a cup of coffee or milk or fruits juice alongwith a few biscuits or fruit. The donor needs no other special diet. A routine balanced diet is adequate. The donor's blood gets replenished within 24 - 48 hours.

The body replaces blood volume or plasma within 24 hours. Red cells need about four to eight weeks for complete replacement.

Three months time between donations is a very safe interval.

Yes, if the donor has suffered from any of the under-mentioned diseases: - Fever: He should not have suffered from fever for the past 15 days. Jaundice: A donor should not have his blood tested positive for AUSTRALIA ANTIGEN. Blood transmitted diseases: Like Syphilis, Malaria, Filaria etc. debar a donor from donating blood till he is treated and is free from them. Drugs: If a donor is taking drugs like Aspirin, anti-hypertensive, anti-diabetics, hormones, corticosteroids etc., he is unfit to donate blood. AIDS. No person having HIV positive can be allowed to donate blood.

Yes, blood donation is a noble, selfless service! It gives the donor a feeling of joy and contentment. Also this is an expression of love for Mankind, as blood knows no caste, colour, creed, religion or race, country, continent or sex.