Only 7% of the world's population is O negative. It is also the most preferred blood group for emergency transfusions, as type O negative red blood cells can be given to any blood type. However, an O negative recipient can receive blood only from a donor who is O negative.

Though our blood appears to be the same when seen from the naked eye, there surely are certain differences which can be seen under a microscope. Our blood contains various components including the red blood cells, white blood cells, plasma, and antigens. Antigens are the substances found on the membrane of the red blood cells, and they may be in the form of proteins, sugars, glycolipids, and so on, as per the specific blood group. Yes, each blood group has a specific antigen, and it is on the basis of the presence or absence of these antigens that our blood groups are classified.

Understanding the Blood Group System

The International Society of Blood Transfusion (ISBT) acknowledges 32 different human blood group systems, out of which, there are two systems that are widely accepted―the ABO and the Rh blood group system. The ABO system is based on the presence or absence of two antigens―A and B―resulting in the classification of 4 blood groups. These are:

Group A: The red blood cells contain A antigen and have B antibody in the plasma.

Group B: The red blood cells contain B antigen and have A antibody in the plasma.

Group AB: The red blood cells contain both A and B antigens but do not have neither A nor B antibody in the plasma.

Group O: The red blood cells contain neither A nor B antigen but have both A and B antibodies in the plasma.

The Rh system is based on the presence or absence of the antigen rhesus (Rh) in the red blood cells. If this antigen is present, then the blood group is called Rh positive. If the antigen is not there, the blood group is Rh negative. It is based on this factor that your blood group is classified as negative or positive. Therefore, there are 8 blood groups based on this system. These are: A positive, A negative, B positive, B negative, AB positive, AB negative, O positive, and O negative.

O Negative Blood Group: The Universal Red Blood Cells Donor

Every year, approximately 5 million people need blood transfusions in the United States of America. There are many instances wherein the doctors need the blood immediately and cannot afford to spend time on checking the blood group of the patient in need. In such a situation, guess who comes into rescue? Yes, the donor with blood type O negative. In fact, this blood type is preferred even when babies need blood transfusions, or when specialized procedures are needed to be conducted on unborn babies.

The property that makes O negative a desired blood group in blood banks, is the fact that it contains none of three antigens: A, B, and Rh. The antigens present in the red blood cells evoke the immune system to respond. For example, if your blood type is A positive, you have both the A and Rh antigens present in your RBCs. If a B positive donor gives you his blood, your immune system will respond to eliminate the B antigen of the B positive blood type because this antigen is foreign to your body. However, because O negative has none of the antigens present in it, the immune system will not generate any response to fight, thereby accepting the blood transfusion.

O Negative Blood and Pregnancy

People with O negative blood type are universal donors, but not universal recipients. This fact can create certain complications during pregnancy. O negative does not have the Rh antigen, which means it comes under the category of Rh negative blood type. In this case, if the expecting mother is Rh negative and the father is Rh positive, then there are chances that the baby may inherit the Rh antigen from the father. If this happens, then problem may arise when the fetus' blood (Rh positive) mixes with the mother's Rh negative blood, which often is the case during pregnancy.

The mother's immune system may identify the Rh factor as a foreign antigen, and therefore generate antibodies to attack the fetus' red blood cells (as they contain the Rh antigen). This may cause your baby to have a condition called hemolytic disease. It can cause severe damage to the unborn baby, including a miscarriage. There are also chances of stillbirth, or death of the infant shortly after birth.

The solution to this problem is as simple as this: An injection containing a blood product called the Rh immunoglobulin (RhIg) is given to the mother during pregnancy and after the baby is delivered. This prevents the mother's immune system from creating antibodies against the Rh positive fetus during pregnancy. Each pregnancy requires the RhIg treatment.

The Right Diet for O Negative Blood Type

You might have heard of eating right, but eating according to your blood type is something unusual, right? It is said that there is a specific diet for each blood type, and if the person eats according to their blood type, various health complications may be curbed beforehand. It was Dr. Peter J. D'Adamo, who brought this concept to the forefront through his medical and genetic research. He believed that a person's blood type is the ultimate reason why each and every individual is biochemically unique. He also wrote a best selling book based on this concept, titled, EAT RIGHT FOR YOUR TYPE, which explains 4 diets for 4 blood groups (A, B, AB, and O). This means that the diet for people with O positive and O negative blood group, is the same.

According to Dr. D'Adamo, they should eat a high protein, lean diet. In fact, this diet will help them lose weight. On the contrary, consumption of wheat, legumes, and whole grains should be kept minimum as they may promote weight gain. People with blood type O are likely to suffer from health conditions, such as ulcers and thyroid problems. Therefore, following the ideal diet for blood group O would help in keeping these health problems at bay, while giving your body the complete benefits as per your genetic inheritance.

Personality Traits of O Negative Blood Type

As per the Japanese convention, a blood type is supposedly the indicator of one's personality. They believe that the blood type of a person can reveal many secrets of a person's traits, mindset, and compatibility with others. According to Japanese beliefs, people having blood group O are born leaders! They are independent, self-confident, determined, competent, and intuitive. They are also known to be passionate, loyal, and actual trend setters. However, on the negative side, they can also become extremely egocentric, unpredictable, indifferent, and doubtful. They also have the tendency of becoming absolute workaholics.

Note.― Like the diet, the Rh factor is not considered while deciding the personality types as well.

It is very important for everyone to be aware of their own blood type which can be found out with the help of a simple blood test. If you happen to be an O negative, then consider it as a blessing that you have the power to help save the lives of millions through donating your blood. Experts suggest to donate blood once in every four months, if possible, to ensure your health safety. Please consult with a trusted medical expert before donating blood, as certain factors―such as using antibiotics, having infections, a medical condition (jaundice), having a tattoo, or piercing in the past 4 months, etc.―may prohibit you from giving your blood.

Disclaimer: This Buzzle article is for informative purposes only, and should not be used as a replacement for expert medical advice.