Anemia

Anemia

Anemia is the condition where there is too little of the biologic molecule called hemoglobin in the blood. Hemoglobin contains the central care iron. It carries oxygen from the lungs to the tissues and helps bring carbon dioxide back to the lungs. In a healthy red blood cell there are approximately 280 million molecules of hemoglobin. Each molecule of hemoglobin can carry four molecules of oxygen to the tissues. If there is too little hemoglobin, or if the hemoglobin is abnormal, the oxygen-carrying function of the blood is decreased.

The laboratory uses different techniques to measure the hemoglobin. One technique is to pass a small quantity of electricity through a blood specimen, and from alterations in the current flow; it is possible to calculate hemoglobin content. In another test, a small pipette of blood is spun down on a centrifuge. The percentage of the total blood which is red blood cells is called the hematocrit. Another test is to look at the red cells under a microscope to see if they are too big or too small. The amount of iron in the blood can be measured. The normal hemoglobin value would be 13 to 15, and a normal hematocrit would be about 36 to 46. Values tend to run a little higher in men than in women. The values tend to be higher in people with chronic lung disease and certain kinds of heart disease.

If a doctor finds you to be anemic, there are three possible major causes. One is that you are losing, or have lost, blood from somewhere. A second possibility is that you are not making enough blood cells. The third possibility is that the red blood cells are breaking down somewhere within the body.

The first category would include rapid blood loss such as through an injury or in childbirth. Some people can lose a lot of blood through a bleeding stomach ulcer. It usually takes a matter of time to replace the fluid in the blood system so that measurements of hemoglobin and hematocrit will be accurate. In these cases an estimate of blood loss would guide the necessity of transfusion blood to be given. There are other bleeding processes which are slower, and more accurately reflect in the hemoglobin and hematocrit values. One might be from a colon polyp or colon cancer. Sometimes stomach ulcers can bleed slowly with the only evidence being black tarry bowel movement and abnormal labs. Another might be heavy menstrual periods. Another clue to this situation is that under these circumstances the red blood cells are made smaller and with less hemoglobin content, which can be seen under a microscope.

The second type of anemia is when the body just doesn’t manufacture enough red blood cells. As most people know, the red blood cells are manufactured in the marrow of bones. Sometimes the marrow can literally be sick. An example of this is called the anemia of chronic disease. Sometimes there can be a cancer in the marrow which decreases its ability to manufacture red blood cells. Alcohol when used chronically and in excessive amounts can adversely affect the marrow, as can certain drugs which cause a low red cell manufacturing condition called aplastic anemia. Chemotherapy in particular can affect the blood producing capacity of the marrow. Lead, which used to be a major ingredient in paint, affected the marrow in children. If one has chronic kidney disease, the kidneys do not make enough of the hormone, erythropoietin, which stimulates the marrow to make red blood cells.

The third type of anemia is when the red cells are manufactured with some condition which affects their longevity and structure. Sickle cell anemia is one example of this. It is an inherited disease where there is abnormal hemoglobin which breaks down and literally causes the cells to take on a sickle shape. There is abnormal hemoglobin in the diseases called thalassemia, where the red cells are likewise abnormal. The spleen acts as a filter and removes these abnormal cells from the circulation causing it to become swollen and tender. When the hemoglobin is released from the cells it is taken up by the liver where it is broken down into bilirubin which can be measured as increased under these circumstances.

The symptoms of anemia depend on several factors, including how rapidly the blood is lost. Under long term circumstances the person might have some exertional fatigue and perhaps pale conjunctivae inside the eyelids which are normally pink. Under acute circumstances the person might pant, have chest pain, feel like they are going to faint, have low blood pressure and an elevated pulse. Young people are more tolerant of anemia than older people.

The most common type of anemia is iron-deficiency anemia. Once the underlying condition is corrected which is causing the deficiency, this is easily treated with supplemental iron. If people either take in too little, or are unable to absorb vitamin B12, they become anemic called pernicious anemia and form red cells which are too large. The same is largely true for folic acid, as seen in chronic alcoholics and some vegetarians. Once again, treatment becomes replacing the vitamins which are deficient. The diminished amount of erythropoietin in chronic kidney disease can be supplemented with shots of this hormone. Of course, in the case of a large and acute blood loss, transfusion of red blood cells can be accomplished.

So, here’s the bottom line. Anemia is an abnormal condition. However it is most often a sentinel for other underlying medical conditions which need to be diagnosed and treated. Some are easily treated; some might require surgery, chemotherapy, or such remedies as treatment of chronic kidney disease. A primary care provider should be able to initiate the evaluation and make referrals as necessary. One thing is for sure: you’ll feel a lot better when your anemia is successfully treated.

John Drew Laurusonis M.D.
Doctors Medical Center