Anemia is a condition that affects your red blood cells. Your red blood cells carry oxygen from your lungs to the rest of your body. Hemoglobin is the protein in red blood cells that allows them to carry oxygen. Your body needs iron in order to make hemoglobin.
People who have anemia don’t have enough hemoglobin. The most common cause of anemia is when your body doesn’t make enough hemoglobin because it doesn’t have enough iron.
This is called iron deficiency anemia.
Another common type of anemia is when your body doesn’t have enough red blood cells, but the red blood cells you do have are normal in size. This is called normocytic (say: “normo-sit-tic”) anemia.
his type of anemia was thought to occur as part of a chronic disorder, most often infection, inflammatory disease (especially RA), or cancer; however, the same process appears to begin acutely during virtually any infection or inflammation.
Three pathophysiologic mechanisms have been identified:
Slightly shortened RBC survival occurs via unknown mechanisms in patients with cancer or chronic granulomatous infections.
Erythropoiesis is impaired because of decreases in both erythropoietin (EPO) production and marrow responsiveness to EPO.
Intracellular iron metabolism is impaired.
Reticuloendothelial cells retain iron from senescent RBCs, making iron unavailable for Hb synthesis. There is thus a failure to compensate for the anemia with increased RBC production.
Macrophage-derived cytokines (eg, IL-1β, tumor necrosis factor-α, interferon-β) in patients with infections, inflammatory states, and cancer cause or contribute to the decrease in EPO production and the impaired iron metabolism.
What are the symptoms of anemia?
- Often, no symptoms
- Feeling tired
- Unusual shortness of breath during exercise
- Unusual food cravings (known as pica)
- Fast heartbeat
- Cold hands and feet
- Brittle nails or hair loss
- Dizziness or lightheadedness
What can cause low iron levels?
A number of things can cause low iron levels in your body:
Diet. You may have low iron levels if you don’t eat enough foods high in iron. This is mostly a problem for children, young women who follow “fad” diets and people who don’t eat meat.
Inability to absorb iron. The iron in your food is absorbed by the body in the small intestine. Diseases that affect your small intestine’s ability to absorb nutrients, such as Crohn’s disease or celiac disease, may cause low iron levels in your body.
Some foods or medicines, including milk, antacids or stomach acid-lowering medicines, also can prevent your body from absorbing iron.
Growth spurts. Children younger than 3 years of age grow so fast that their bodies may have a hard time keeping up with the amount of iron they need.
Infants who drink cow’s milk in the first year of life are at risk for iron deficiency anemia. It’s the most common dietary cause of iron deficiency in infants.
Cow’s milk does not have enough of the iron infants need to grow and develop.
Do not give cow’s milk to your infant in the first year of life. Breastfed infants who do not eat iron-rich foods like iron-fortified cereal or take an iron supplement after the fourth month of life are also at risk of iron deficiency anemia.
Toddlers (12 to 24 months of age) who drink a lot of cow’s milk, have a diet low in iron, or already had iron deficiency as an infant are also at risk.
Pregnancy. Women who are pregnant or who are breastfeeding need more iron than women who are not pregnant or breastfeeding.
That’s why pregnant women often are tested for anemia and why they need to eat more iron-rich foods or take a daily iron pill.
When you’re pregnant, your body makes more blood to share with your baby. You may have up to 30% more blood than when you’re not pregnant.
If you don’t have enough iron, your body can’t make the red blood cells that it needs to make this extra blood.
The following may increase your risk of anemia during pregnancy:
- Vomiting a lot from morning sickness
- Not getting enough iron-rich foods
- Having heavy periods before pregnancy
- Having 2 pregnancies close together
- Being pregnant with twins, triplets or more
- Becoming pregnant as a teenager
- Losing a lot of blood (for example, from an injury or during surgery).
If you are pregnant and are not getting enough iron, you are at risk of developing iron-deficiency anemia.
Blood loss. Heavy periods may cause low iron levels in women. Internal bleeding, usually in the digestive tract, also can cause blood loss.
A stomach ulcer, ulcerative colitis, cancer, or taking aspirin or similar medicine for a long time can cause bleeding in your stomach or intestines.
Genetic diseases. If you have sickle cell disease or thalassemia, your body has trouble producing healthy red blood cells, which can lead to anemia.
You’re also at risk of passing these diseases on to your unborn baby. If you or someone in your family has one of these diseases, talk to your doctor about how to prevent or treat anemia while you’re pregnant.
What causes normocytic anemia?
Normocytic anemia can be a problem you were born with (called congenital) or it can be caused by an infection or disease (called acquired).
The most common cause of the acquired form of normocytic anemia is a chronic (long-term) disease.
Chronic diseases that can cause normocytic anemia include kidney disease, cancer, rheumatoid arthritis and thyroiditis.
Some medicines can cause you to have normocytic anemia, but this does not happen often.
Symptoms and signs of underlying disorder
CBC and serum iron, ferritin, transferrin, and transferrin receptor
Clinical findings are usually those of the underlying disorder (infection, inflammation, or cancer).
Anemia of chronic disease is suspected in patients with microcytic or marginal normocytic anemia with chronic infection, inflammation, or cancer.
If anemia of chronic disease is suspected, serum iron, transferrin, transferrin receptor, and serum ferritin are measured. Hb usually is > 8 g/dL unless an additional mechanism contributes to anemia (see also Differential Diagnosis of Microcytic Anemia Due to Decreased RBC Production).
If there is infection, inflammation, or cancer, a serum ferritin level of slightly < 100 ng/mL suggests that iron deficiency is superimposed on anemia of chronic disease.
However, because serum ferritin may be falsely elevated as an acute-phase reactant, the serum transferrin receptor measurement may better differentiate iron deficiency from anemia of chronic disease when serum ferritin is > 100 ng/mL.
Treatment of underlying disorder
Recombinant EPO and iron supplements
Treating the underlying disorder is most important. Because the anemia is generally mild, transfusions usually are not required, and recombinant EPO may be offered.
Because both reduced production of and marrow resistance to EPO occur, the EPO dose may need to be 150 to 300 units/kg sc 3 times/wk. A good response is likely if after 2 wk of therapy Hb has increased > 0.5 g/dL and serum ferritin is < 400 ng/mL.
Iron supplements (see Iron Deficiency Anemia : Treatment) are required to ensure an adequate response to EPO. However, careful monitoring of Hb response is needed because adverse effects (eg, venous thromboembolism, MI, death) may occur when Hb rises to > 12 g/dL.
Almost any chronic infection, inflammation, or cancer can cause anemia; Hb usually is > 8 g/dL unless an additional mechanism contributes.
Multiple factors are involved, including shortened RBC survival, impaired erythropoiesis, and impaired iron metabolism.
Anemia is initially marginally normocytic and then becomes microcytic.
Measure serum iron, transferrin, transferrin receptor, and ferritin levels.
Serum ferritin levels tend to be > 100 ng/mL unless iron deficiency also is present.
Treat the underlying disorder and give recombinant EPO.
What problems can iron deficiency anemia cause in my child?
Iron deficiency anemia can cause your infant or toddler to have mental, motor or behavior problems. These problems can be long lasting even after treatment fixes the anemia.
What problems does anemia cause during pregnancy?
If anemia isn’t treated, it can increase your risk of having your baby too early or having a baby who doesn’t weigh enough.
You’ll also be at risk of needing a blood transfusion if you lose a lot of blood during delivery. Anemia may also be associated with postpartum depression (depression after delivery) in new mothers.
Rarely, mothers who have severe iron-deficiency anemia may pass along problems associated with low iron to their babies.
This can lead to growth problems and mental delays. However, developing babies usually take as much iron as they need from their mothers.
Getting treatment for your iron-deficiency anemia can almost always prevent these problems.
Can iron pills cause problems?
Iron pills can cause stomach upset, heartburn and constipation. Be sure to talk to your doctor before you take extra iron pills or vitamins.
Lack of iron in your diet may not be the cause of your anemia and too much iron is not good for you. If your doctor prescribes iron supplements, be sure to tell your doctor about any discomfort you notice.
Can anemia be prevented?
Some types of anemia can be prevented, such as those caused by diet. You can help prevent this type of anemia by increasing the amount of iron in your diet.
How can I increase the iron in my diet?
Eat more foods that are high in iron. Your body best absorbs iron that comes from meat. Eating a small amount of meat along with other sources of iron, such as certain vegetables, can help you get even more iron out of these foods.
Taking vitamin C pills or eating foods high in vitamin C, such as citrus fruits or juice, at the same time you eat iron-rich foods or take your iron pill can also help your body absorb the iron.
Some foods prevent your body from absorbing iron, including coffee, tea, egg whites, milk, fiber and soy protein. Try to avoid these foods when you’re eating food high in iron.
- Foods high in iron
- Red meat
- Dried fruits such as apricots, prunes and raisins
- Beans, especially lima beans
- Green leafy vegetables, such as spinach and broccoli
- Blackstrap molasses
- Whole grains
- Iron-fortified foods like many breads and cereals (check the label)
How can I prevent iron-deficiency anemia during pregnancy?
You can’t always prevent anemia during pregnancy, but eating foods rich in iron can help. Doctors recommend that pregnant women eat at least 27 mg of iron daily.
Most doctors also recommend that pregnant women take a supplement that contains 30 mg of iron each day. (Most prenatal vitamins contain at least this amount.)
Foods with vitamin C—such as strawberries and citrus fruits—help your body absorb iron. Eat these foods with foods that are high in iron to help with absorption.
For example, if you’re taking an iron pill, take it with orange juice or another food high in vitamin C. Some foods can block iron absorption.
These include milk, soy protein, egg yolks, coffee and tea. Avoid these foods when eating iron-rich foods. Antacids and some other medicines that contain calcium also block iron absorption.
Your doctor can tell you more about which medicines to avoid if you’re trying to boost your iron levels.
How do I prevent iron-deficiency anemia in my child?
If you use iron-fortified formula, do not give your child vitamin drops with iron.
This combination provides too much iron and is not healthy. If you decide to stop breastfeeding before your infant is 12 months of age, use iron-fortified formula. Do not use low-iron formula.
After your child is 12 months old, if you stop breastfeeding or using iron-fortified formula, you should feed your toddler meat, chicken, fish, whole grains, enriched bread and cereal, dark green vegetables, and beans.
Vitamin C is also important because it helps the body absorb iron.
You should limit your child to less than 24 oz of cow’s milk per day. (That’s 3 cups of milk.) You might try giving your child yogurt and cheese. Ask your doctor if you should continue to give your child vitamins with iron.