Anemia (Low hemoglobin): A-to-Z Guide from Diagnosis to Treatment to Prevention

Blood is a straw-colored liquid packed with red blood cells (which deliver oxygen to the body), white blood cells (which provide protection from infections), and platelets (little clumps that help the blood clot when needed). The red blood cells carry oxygen from the lungs to every part of the body. They also give the blood its characteristic dark red color. This steady supply of oxygen to the body’s tissues is necessary for health, for growth, and for life itself.Inadequate red blood cells result in anemia.

What is it?

When you don’t have adequate red blood cells in your blood, you have anemia.

Normally about 1 percent of the red blood cells retire every day, to be replaced by about the same number of fresh, young red blood cells. Each red blood cell lives approximately 120 days.

Anemia occurs when the production of red blood cells is insufficient, when too many red blood cells are destroyed, or when blood is lost (through bleeding).

Who gets anemia?

There are many, many reasons a child might become anemic.

The most common reason for a child to be anemic is an inadequate supply of iron. Iron is a mineral that your body needs in order to make red blood cells. Children who lack enough iron will make small, pale, ineffective red blood cells.

Low levels of other nutrients, such as folic acid, can also be a cause. This is most common in children primarily fed goat’s milk, which is low in folic acid.

Many viral illnesses will cause brief anemia in otherwise healthy children.

Some children have red blood cells that are fragile and easily broken. This often occurs in hereditary conditions.

Sickle cell anemia is one type of hereditary anemia where the red pigment, called hemoglobin, is not made normally.

Some children become anemic from blood loss. This can either be obvious blood loss, or long-term low-grade blood loss, perhaps in the stool. A cow’s milk allergy, for instance, is a common cause of hidden blood loss.

Exposure to toxins, such as lead, can also cause a child to become anemic.

What are the symptoms?

Mild anemia might cause no obvious symptoms.

Anemic children may feel tired, weak, and cranky. It can cause pale skin, headaches, and a poor appetite. Kids with anemia tend to get sick more often. Their brains and muscles are also affected.

Prolonged or severe anemia can cause marked irritability, decreased appetite, and slowed growth. In very severe cases, children can even go into heart failure.

Some specific types of anemia have specific symptoms, such as the pain crises associated with sickle cell.

Is anemia contagious?

It is not contagious, although some of the underlying causes can be.

How long does it last?

Anemia will last until bone marrow production is able to adequately replenish the supply of red blood cells. How long this takes depends on the degree of anemia and on the underlying cause. Some anemias are only brief episodes while others may last a lifetime.

How is it diagnosed?

Most children get a screening blood test between 6 and 18 months of age to look for anemia. The blood test is important because it can identify anemia before there are any symptoms.

Anemia on the screening blood test is not necessarily caused by iron deficiency, although mild anemia in an otherwise well child is most often caused by iron deficiency.

Further blood tests (and perhaps a search for sources of bleeding) can pinpoint the type of anemia.

How is it treated?

Because there are so many types of anemia, it is important to work with your pediatrician to determine what is really going on.

If the history and physical exam are consistent with iron deficiency, iron supplements may be given for about a month to see if there is a response. If the anemia has not improved in this time, further testing is warranted before further treatment.

How can anemia be prevented?

See articles on iron deficiency, lead exposure, and sickle cell anemia for specific prevention strategies for different types.

Last medical review on: July 27, 2019
About the Author
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Dr. Greene is a practicing physician, author, national and international TEDx speaker, and global health advocate. He is a graduate of Princeton University and University of California San Francisco.
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