Anemia and Fatigue

Are you anemic?

Anemia is a sneaky condition. You can have it and not know it. Yet you should not ignore it. Left untreated, anemia can lead to a lack of energy, breath and color in your cheeks, and more seriously to strokes, heart attacks and even death. A diagnosis of anemia also can raise the possibility of other conditions that might require attention, such as an ulcer, polyp or cancer.

Is it fatigue?

When you feel that performing one more task on a Saturday afternoon would be akin to running a marathon, you almost certainly are fatigued. But that doesn't necessarily mean you're anemic. Fatigue, or weariness, can overcome anyone who has expended significant energy, either physically or emotionally. Anemia, however, is another story.

What is anemia?

Anemia is a medical disorder. More specifically, it is a condition in which the production of red blood cells or hemoglobin (the protein that carries oxygen) is less than what your body requires. As a result, your blood system is unable to efficiently carry oxygen from your lungs to the rest of your body.

Anemia may occur when you lose blood, are lacking an important nutrient, or have a condition that causes the over-destruction of red blood cells. For example, if you lose blood suddenly, through an accident or surgery, or gradually, through chronic nosebleeds, heavy menstrual bleeding or stomach ulcers, your body will react by drawing water into the bloodstream. This dilutes the quantity of red cells in the blood vessels, diminishing their ability to carry oxygen.

Similarly, if the quantity of red blood cell and hemoglobin production is decreased (due to a lack of one of their required nutrients, such as iron, vitamin B12 or folic acid) or the natural rate of red blood cell destruction is increased (through conditions such as enlarged spleen or immune system malfunction), anemia may result.

What is the prevalence of iron deficiency anemia?

The prevalence of iron deficiency anemia depends on age. The prevalence is higher in infants under two years of age, adolescent females and menstruating women.

What is fatigue?

Fatigue, more simply, is a debilitating feeling of weariness or exhaustion. It may make you feel as if everything you do takes just a little more effort than usual. Or it may make you think that being a "couch potato" suddenly has appeal.

Are they related?

Anemia can, and often does, cause fatigue. In general, that is because the diminishment of the oxygen supply to your heart and other vital organs drains you of energy.

How do they differ?

While anemia is a medical disorder, fatigue is not. Fatigue may result from anemia or other medical conditions. More generally, it can also result from simple physical or emotional exertion or stress.

Understanding symptoms

Often anemia will be diagnosed before any symptoms are evident. Long standing or severe anemias are more likely to have symptoms.

Anemia's symptoms develop slowly. When someone says you look more pale than usual, for example, that could be your first clue. To check for yourself, look under your eyelids, lips and nail beds. If these areas look more wan or lifeless than usual, it may be a sign of anemia.

As anemia progresses, other symptoms may include weakness, fatigue, dizziness and difficulty exercising. It may also include shortness of breath or rapid heartbeat. Certain types of anemia may also have characteristic symptoms. A vitamin B12 deficiency, for example, may lead to tingling or loss of sensation in your hands or feet.

Diagnosing anemia

Because anemia can precede any symptoms you might experience, the disorder is most commonly diagnosed through blood tests. A test for anemia is included in a CBC, or complete blood cell count, an analysis of a blood sample drawn at your doctor's office.

Understanding your blood counts

In general, anemia can be detected by measuring the red blood cells and hemoglobin in your blood sample. More specifically, your doctor may measure levels of iron and transferrin (the protein that carries iron) or vitamin B12. Or your doctor may look for the existence of large red cells, or microcyte, small red cells.

Megaloblasts, or unusually large red blood cells, can be seen under a microscope or detected on the CBC and may suggest a vitamin B12 deficiency, also known as pernicious anemia. If less than 10 percent of the transferrin in your blood sample is permeated with iron, it may indicate iron deficiency anemia, and small red cells will be seen.

How diet and nutrition can make a difference

Your body requires about 1 milligram to 2 milligrams of iron a day. But some sources of iron are better than others, and some foods and vitamins can interfere with your absorption of this important nutrient. Meat, for example, is an excellent source of iron. But vegetable fiber and bran can bind with iron and, as result, diminish your body's ability to absorb it. In contrast, vitamin C can increase your ability to absorb iron.

But while eating right can help, in some cases, it is not enough to treat anemia. In many cases, your doctor may prescribe an iron supplement.

Last Updated: 9/24/2002
The Johns Hopkins University 1996-2003.  All rights reserved.  This information is not intended to provide advice on personal medical matters, nor is it intended to be a substitute for consultation.