What Is Anemia?
Anemia means that your hemoglobin level is below normal. Hemoglobin is a protein in red blood cells. It binds oxygen and carries it to the body’s cells. Usually, people with anemia also have a decreased number of red blood cells. People with anemia have less capacity to take oxygen from the lungs and deliver it to the rest of the body. Anemia may occur when:
- You lose blood
- You cannot produce enough new red blood cells in your bone marrow, perhaps because you are deficient in one or more nutrients (such as iron)
- You have a condition that causes red blood cells to be destroyed before the end of their usual 120-day life span
What Is Fatigue?
Fatigue is a 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. There is less oxygen supply to your heart and muscles, so you have less energy to perform your usual activities. However, most people with fatigue do not have anemia. There are many other causes of fatigue, such as depression, emotional stress, insomnia, physical exhaustion, and a variety of medical problems.
The Symptoms Of Anemia
When anemia develops slowly, your body is able to partially compensate for the lack of red blood cells, so many people are not aware they have anemia until it is diagnosed on a routine blood test. If the hemoglobin level falls quickly or gets too low over a longer period of time, you will feel the difference.
The first symptoms of anemia are often mild weakness and fatigue. As the number of red blood cells drops further, common symptoms include shortness of breath, lightheadedness (especially with standing), rapid heartbeat, pale skin, marked weakness and difficulty exercising.
More severe anemia may lead to lethargy and confusion, and in patients with pre-existing heart or lung disease, may result in potentially life-threatening complications such as congestive heart failure, angina (chest pain), or heart attack.
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. This is an analysis of a blood sample drawn at your doctor’s office or in a laboratory.
Poor nutrition may contribute to inadequate red blood cell production — especially deficiencies in iron and certain types of vitamin B. When an increased production of red blood cells (RBCs) is necessary — such as during pregnancy or after an episode of bleeding — these nutrients are even more critical. Iron and vitamin B supplements are often prescribed to prevent anemia.
Iron deficiency is the most common cause of anemia in the United States. It occurs when the body either has depleted all iron stores or is unable to use the iron available to make adequate amounts of hemoglobin (the protein in the RBC which carries oxygen). For Americans, however, lack of dietary iron is rarely the sole cause of this anemia.
Usually, people have blood loss as well. Young women are at particular risk, because of monthly blood loss with menstruation. Up to 10 percent of women in their reproductive years have iron deficiency, and, in about half of those cases, it is severe enough to cause anemia. Pregnant women also are at risk, which is why prenatal vitamins containing extra iron are recommended during pregnancy.
Iron-deficiency anemia is less common in men and in postmenopausal women in the United States. Low iron levels in these groups is a warning that abnormal bleeding could be occurring due to undiagnosed medical conditions such as ulcer disease or colon cancer.
The highest amounts of iron are found in meat, spinach, raisins, lentils and enriched flour. Iron is absorbed most efficiently, however, from red meat — which is why pre-menopausal women who don’t eat much meat are at particular risk for iron-deficiency anemia. Other factors also contribute to how much iron is absorbed in the body. Vitamin C enhances the absorption of iron from the intestine, so if you combine foods with iron and vitamin C, you will increase the amount of iron absorbed. Citrus fruits are well-known for their vitamin C content, but many vegetables are also a good source of vitamin C, such as tomatoes, cauliflower, broccoli and potatoes.
Folic acid (folate) deficiency
A lack of folic acid — one of the B-complex vitamins — may cause another kind of anemia. Folic acid is critical to the body’s metabolism of amino acids, as well as to the formation of healthy red blood cells. In folic-acid deficiency, the RBCs produced are unusually large and have a shortened life span. Folic acid is a water-soluble vitamin and thus cannot be stored in any great quantity in the body. Therefore, it must be replenished by diet on a regular basis; the body will exhaust its supply of folate in about three months if the diet is deficient. Folic-acid deficiency may occur among older people and heavy alcohol drinkers because they are at risk of eating a poor diet. There also is an increased demand for folate during pregnancy, and in medical conditions that cause rapid RBC destruction, such as sickle cell anemia and certain cancers. In these cases, folate supplements usually are prescribed. In addition, adequate folic acid intake is necessary for women who may become pregnant to help prevent birth defects.
Folate is found in liver, fortified cereals, lentils, beans, green leafy vegetables such as spinach, collards, asparagus, and broccoli, orange juice, and in products made from folate-fortified flour. As with iron, not all of the folic acid you eat is absorbed by your body. The amount absorbed depends on the type of food and the method of cooking it. It’s important to avoid overcooking vegetables, and avoid leaving them out at room temperature for an extended period of time; this can significantly decrease folic-acid concentrations.
Vitamin B12 deficiency
Vitamin B12 deficiency, like folate deficiency, causes anemia — unusually large RBCs are produced with a shortened life span. Older Americans may have B12 blood levels that are below the optimal range even when there is no anemia. This usually is due to an inability to absorb vitamin B12, rather than a dietary deficiency, although strict vegetarians are at risk, because vitamin B12 is found only in animal products.
Another cause of vitamin B12 deficiency is pernicious anemia, an autoimmune disease in which the immune system attacks stomach cells, decreasing the amount of a protein called intrinsic factor. This protein is essential to the absorption of vitamin B12 from food. Vitamin B12 deficiency also can develop as a complication of gastrointestinal surgery and certain diseases of the intestine, preventing adequate absorption.
Good sources of vitamin B12 include liver, tuna, cottage cheese, yogurt and eggs. Most standard multivitamin supplements also provide the recommended daily allowance of vitamin B12.
Anemia And Cancer
Anemia is common in patients with cancer. Anemia is defined by a reduced amount of red blood cell volume and a decline in hemoglobin, the part of blood that carries oxygen to the body’s tissues. It is often associated with fatigue that may be debilitating.
Anemia can occur for several reasons. The most common cause is a decrease in production of new red blood cells by the bone marrow. Many of the cancer chemotherapy drugs significantly depress red blood cell formation. Local radiation therapy is less damaging but can still cause anemia. Other causes of anemia include bleeding related to the tumor itself and insufficient intake of iron and other nutrients because of poor appetite.
About three in four cancer patients will experience fatigue. Anemia may be a significant factor, and correcting the anemia results in an improved sense of well-being. Most people worry that if they ever develop cancer, pain will be the worst part. But for many cancer patients, the fatigue is even more disabling. Treatment of anemia related to cancer includes vitamins, iron, erythropoietin injections (a medication to stimulate the bone marrow to make more red blood cells) and blood transfusions. Also, there are things you can do to reduce fatigue during cancer treatments:
- Exercise lightly, including short walks.
- Rather than having three large meals a day, eat snacks and smaller meals throughout the day.
- Schedule activities for the time of day when your energy is usually at its peak.
- Always leave time for a short nap or rest between activities.