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Blood and the Body

A Closer Look at Anemia

Anemia is a condition of having too few healthy red blood cells (RBCs). It is the most common kind of blood condition. In fact, more than 3 million people in the United States have Anemia. While it is a common condition, anemia significantly affects your health and can even be life threatening. In infants, children and adolescents it can affect mental and motor skill development.

What causes Anemia?

There are several main causes of anemia. The first is not having enough iron to make red blood cells. The second is having another condition that limits RBC production. The third main cause is having a condition that leads to increased destruction of the red blood cells.

Not Having Enough Iron to Make Red Blood Cells

Not having enough iron (iron deficiency) is the most common cause of anemia. RBCs contain a protein molecule called hemoglobin, which is designed to carry oxygen throughout the body. Each molecule of hemoglobin contains four iron atoms, and each iron atom carries one molecule of oxygen. RBCs are broken down and recycled about every 4 months. Iron is a key ingredient and new RBCs are built from both recycled iron and new iron you get from your diet. If you don’t have enough iron you can’t make enough new red blood cells to replace the cells that have worn out. There are several reasons that you may not have enough iron: blood loss, not getting enough iron through your diet, not having enough iron during times when you need more.

Blood loss is the most common reason for not having enough iron and the most common cause of anemia. It can be sudden, such as an injury or surgery or childbirth. It can also be ongoing such as having heavy menstrual periods, cancer of the colon, or medicines that you take long-term like aspirin. Sometimes, you may not even know that you are losing blood. If you lose enough blood you may not have enough iron to make red blood cells.

If your diet doesn’t have enough iron, you won’t be able to make enough RBCs. Also, there are some medical conditions, such as Crohn’s Disease, that prevent you from absorbing iron even when the foods you eat have enough. There are other nutrients also needed to make red cells including folic acid (folate) and vitamin B12.

Conditions Decreasing Red Blood Cell Production

Some conditions affect your ability to make new RBCs. Examples include certain toxins (e.g. pesticides & arsenic), kidney disease, cancers that affect the bone marrow (e.g. leukemia and myeloma), cancer treatments, and heart failure.

Increased Red Blood Cell Destruction

There are several conditions that cause increased destruction of red blood cells and cause anemia. These include inherited conditions (e.g. sickle cell anemia, and thalassemia), drug reactions (e.g. penicillin), and some infections (e.g. malaria).

What are the symptoms of Anemia?

There are many symptoms of anemia; however, a complete blood count (CBC), which measures the number of red and white cells in the blood, is often needed to determine if a person is anemic.

A main symptom of any anemia is feeling tired and not having your usual level of energy for things you do throughout the day. Other symptoms include:

With a mild anemia you may not notice symptoms or they may be limited. As anemia gets worse symptoms increase and can damage parts of your body like the heart and brain. A very serious anemia can be life-threatening.

Anemia in itself is a symptom. Having a low red blood cell count doesn’t tell you the cause, but it does indicate that that something is wrong that is worth investigating.

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This article is a NetWellness exclusive.

Last Reviewed: May 04, 2012

Susan   Wentz, MD, MS Susan Wentz, MD, MS
Director, Area Health Education Center
School of Medicine
Case Western Reserve University