One of the most common appeals from hospitals and different NGOs are the ones to give some to some who have lost some; our blood. There are different types. And throughout the world there are certain blood groups that are easily located. But then again there are a few which are very difficult to find. And rarer still if one can find the exact one where compatibility is not an issue as usually it is. When transferring it from one person to the person, the blood group is not the only factor which has to be considered. There are a variety of other medical factors which play an important role in this.

Of all the types, the O negative blood type is the one that plays as the most elusive. This is because the number of factors which makes up this blood group is the rarest. One of the most interesting factors when it comes to the O negative group is that it is called as the ever charitable blood type. This is because it has the unique ability to be transferred to a person of any blood type and there would be no complications regarding the compatibility issues! This is because they O negative blood group is also known as the universal donor. The factor which is the most crucial one when it comes to compatibility when transfusion of blood is considered is the Rhesus factor. As long as this factor is compatible, the transfusion would be a success. In the case of O negative this is not a problem as this would be compatible.

This is why many of the blood banks and the hospital blood banks are constantly trying to locate people who have this blood group and then try to maintain a constant supply of this type. As and when emergencies arise especially in the causalities, this is the most preferred blood type that they look to transfuse. People believe that people with this rare blood group are truly special. In certain cultures they believe that the ones with this blood group are the ones who would stand out from the crowd and believe that they are leaders in the making.  It is important for the people who have this blood group to watch their diet because this is one factor which plays an important role when it comes to transfusion of blood. If the person who is donating the blood is not healthy, then blood transfusions are discouraged.

Blood types are classified based on the presence or absence of inherent antigenic substances on the surface of red blood cells. The antigenic substances can be proteins, carbohydrates, glycolipids and glycoproteins depending on the blood group system. The International Society of Blood Transfusion (ISBT) has recognized a total of 30 human blood group systems. The ABO system and the Rh (rhesus) system are the most significant blood group systems in human blood transfusion. The ABO system classifies blood into four major types based on the presence of Antibodies A and Antibodies B:

1. Group A – has only the A antigen on red blood cells surface and antibody B in the plasma

2. Group B – has only the B antigen on the surface of red blood cells and A antibody in the plasma

3. Group AB – has both A and B antigens on red blood cells surface (but neither A nor B antibody in the plasma)

4. Group O – has neither A nor B antigens on red blood cells surface but both A and B antibodies are present in the plasma

In addition to the ABO system, while determining the blood type of an individual, the presence or absence of Rh (Rhesus) antigens on the surface of red blood cells is also taken into account and expressed as Rh+ (does have Rh antigen) or Rh– (does not have Rh antigen). The majority of the population is Rhesus positive. The blood type of a person is extremely important in blood transfusion and individuals with o negative blood type are truly the ones who are universal donors meaning that they can donate blood to all blood groups but they can accept blood only from people having the same type of blood. O negative blood type is one of the rarest blood types with less than 1 % of Asian, around 7% of Caucasians and 3% to 4% of African Americans having this blood type. Countries like Spain, Australia, New Zealand and Iceland have the highest population of blood type O negative.

In some countries, it is believed that in order to lead a healthy life, people should eat right as well as live right for their blood type. People with o negative blood type should have similar diet than o positive blood type. Their diet should include vegetables and particularly food with high protein content such as meat, poultry, fish and soya. Blood type O individuals should avoid legumes, grains and beans. It is observed that blood type O individuals have higher level of stomach acid than the other blood types. Therefore type O's should ensure that they eat plenty of fruits to regulate their stomach acidity. Regarding diseases, blood type O's are predisposed to ulcers and thyroid malfunction. In fact, it has been found that the thyroid gland of people with blood type O produce insufficient amount of thyroid hormone. In addition, type O's often have insufficient levels of iodine in their blood, a mineral which is essential for thyroid hormone regulation. This has many side effects such as fluid retention, weight gain and fatigue. It is important that people having blood type O have a diet rich in saltwater fish and kelp which are good sources of iodine to help regulate the thyroid gland. In Japan, blood types are even associated with the personality of an individual. People having blood type O negative are leaders, extroverts, energetic, independent, self confident, jealous, passionate and loyal.