Red blood cells (RBCs) or erythrocytes are the most abundant cells in blood. They contain haemoglobin, an iron-containing protein, which is responsible for oxygen transportation around the body. In order to maintain a healthy amount of RBC in the body, you must incorporate iron, folic acid and vitamins in your their diet. The amount of RBC in the body can be evaluated by doing a simple blood test (RBC count test).
Normal range of RBCs is 4.5 to 5.5 million cells/cubic mm of blood. Low levels of RBC means decreased oxygen supply to the body leading to fatigue and weakness or anaemia. Decreased levels of RBCs are seen in iron deficiency anaemia, thalassemia, stomach ulcers, sickle cell anaemia and certain cancers. If the levels of RBCs are higher than normal, they stick to each other, form clumps and block blood vessels. High levels are seen in case of chronic smokers, alcoholics and in people with long-term lung, kidney, heart or liver disease. RBC counts may also be increased in cases of dehydration, burns, diarrhoea and vomiting.