What Does Anemia Mean?

I seem to be having a theme in the last few weeks!  I’ve been seeing lots of people with blood problems and the most common blood problem is anemia.  WebMD estimates 3.5 million Americans have anemia.  So what’s anemia?

Anemia is a condition where there are less than the normal number of red blood cells in the bloodstream.  Red blood cells function to carry oxygen from the lungs to the tissues where it is used.  Every single cell in your body uses oxygen and they can’t go very long without it.

If you are anemic, either you are losing red blood cells too quickly or you are not making enough to replace the red blood cells that are being lost (or both).  The “red cell mass” (total number of red blood cells in the circulation)  is a balance between new red blood cells being made and old red blood cells being destroyed.  The spleen takes damaged red cells out of circulation and a red blood cell usually has a useful lifetime of 2-3 months.

There are conditions that can increase the rate of loss of red blood cells, including some inherited conditions, infections and medications.  There is also a problem called hemolytic anemia, where the red blood cells break open and release the hemoglobin (the pigment that colors the blood red and actually carries the oxygen).  However, far and away the most common reason to be losing red cells faster than they are replaced is by bleeding.

When I say bleeding most people think of the bleeding that happens when you cut your finger.  That is not nearly enough to make you anemic.  Bleeding significant enough to cause anemia is usually heavy menstrual bleeding over a long period of time, bleeding in the stomach or intestines which can be either fast or slow, or blood loss from major trauma or surgery.

Red blood cells (like all other blood cells) are made in the bone marrow.  There is a hormone made by the kidney called erythropoietin which tells the bone marrow to make more red blood cells.  Kidney problems can decrease erythropoietin levels and lead to anemia.  Also, the bone marrow needs lots of building blocks to generate hemoglobin and red blood cells.  The most important ones are iron, protein, vitamin B12, and folic acid.  Deficiencies of any of these building blocks can lead to anemia.

The first step to treating anemia is to discover the cause.  If it is a deficiency, you replace the building block that is missing.  If it is due to kidney disease there are injectable medications to replace the activity of erythropoietin and stimulate the bone marrow to make red blood cells.  Obviously if there is bleeding we need to find the source and stop the bleeding (ulcers, colon polyps, heavy menstrual periods, etc).

If you think you might be anemic, or you know you’re anemic but don’t know why, please see your doctor.  A simple blood test can make the diagnosis and start the process of finding and fixing the cause.