What Is Iron-Deficiency Anemia?
Iron-deficiency anemia is a common, easily treated
condition that occurs when you don't have enough iron in your body.
Low iron levels usually are due to blood loss, poor
diet, or an inability to absorb enough iron from foods.
Overview
Iron-deficiency anemia is a common type of
anemia.
The term "anemia" usually refers to a condition in which your blood has a lower
than normal number of red blood cells. Red blood cells carry oxygen and remove
carbon dioxide (a waste product) from your body.
Anemia also can occur if your red blood cells
don’t contain enough hemoglobin (HEE-muh-glow-bin). Hemoglobin is an
iron-rich protein that helps carry oxygen to your body.
Iron-deficiency anemia usually develops over time if
your body doesn’t have enough iron to build healthy red blood cells.
Without enough iron, your body starts using the iron it has stored. Soon, the
stored iron gets used up.
After the stored iron is gone, your body makes fewer
red blood cells. The red blood cells it does make will have less hemoglobin
than normal.
Iron-deficiency anemia can cause fatigue
(tiredness), shortness of breath, chest pain, and other symptoms. Severe
iron-deficiency anemia can lead to heart problems, infections, problems with
growth and development in children, and other complications.
People at highest risk for iron-deficiency anemia
include infants and young children, women, and adults who have internal
bleeding.
Outlook
Iron-deficiency anemia usually can be successfully
treated. Treatment will depend on the cause and severity of the condition.
Treatments may include changes to your diet, medicines, and surgery.
Severe iron-deficiency anemia may require treatment
in a hospital,
blood
transfusions, iron injections, or intravenous iron therapy.
What Causes Iron-Deficiency Anemia?
Not having enough iron in your body causes
iron-deficiency anemia. Lack of iron usually is due to blood loss, poor diet,
or an inability to absorb enough iron from the foods you eat.
Blood Loss
When you lose blood, you lose iron. If you
don’t have enough iron stored in your body to make up for the iron loss,
you’ll develop iron-deficiency anemia.
In women, low iron levels may be due to blood loss
from long or heavy menstrual periods or bleeding fibroids in the uterus. Blood
loss that occurs during childbirth is another cause for low iron levels in
women.
Internal bleeding (bleeding inside the body) also
may lead to iron-deficiency anemia. This type of blood loss isn’t always
obvious, and it may occur slowly. Some causes of internal bleeding are:
- A bleeding ulcer, colon polyp, or colon
cancer
- Regular use of aspirin or other pain medicines,
such as nonsteroidal anti-inflammatory drugs (for example, ibuprofen and
naproxen)
- Urinary tract bleeding
Blood loss from severe injuries, surgery, or
frequent blood drawings also can cause iron-deficiency anemia.
Poor Diet
The best sources of iron are meat, poultry, fish,
eggs, and iron-fortified foods (foods that have iron added). If you don’t
eat these foods regularly, or if you don’t take an iron supplement,
you’re more likely to get iron-deficiency anemia.
Vegetarian diets can provide enough iron if the
right foods are eaten. For example, good nonmeat sources of iron include
spinach and other dark green leafy vegetables, certain types of beans, dried
fruits, and iron-fortified breads and cereals.
During some stages of life, such as pregnancy and
childhood, it may be hard to get enough iron in your diet. This is because your
need for iron increases during these times of growth and development.
Inability To Absorb Enough Iron
Even if there's enough iron in your diet, your body
may not be able to absorb it. This may be due to intestinal surgery or diseases
of the intestine, such as Crohn’s disease or celiac disease.
Prescription medicines that reduce acid in the
stomach also can interfere with iron absorption.
Who Is At Risk for Iron-Deficiency Anemia?
Infants and young children, women, and adults who
have internal bleeding are at highest risk for iron-deficiency anemia.
Infants and Young Children
Infants and young children need a lot of iron to
grow and develop. The iron that full-term infants have stored in their bodies
is used up in the first 4 to 6 months of life.
Premature and low-birth-weight babies are at even
greater risk for iron-deficiency anemia. These babies don’t have as much
iron stored in their bodies as other babies do.
Iron-fortified foods for babies or iron supplements,
when used properly, can help prevent iron-deficiency anemia in infants and
young children. Talk to your child's doctor about your child's diet.
Young children who drink large amounts of cow's milk
may be at risk for iron-deficiency anemia. Milk is low in iron, and too much
milk may take the place of iron-rich foods in the diet. Too much milk also may
prevent children’s bodies from absorbing iron from other foods.
Children who have lead in their blood also may be at
risk for iron-deficiency anemia. Lead can interfere with the body’s
ability to make hemoglobin. Lead may get into the body from breathing in lead
dust, eating lead in paint or soil, or drinking water that contains lead.
Women
Women of childbearing age are at increased risk for
iron-deficiency anemia because of blood loss during their monthly periods.
About 1 in 5 women of childbearing age has iron-deficiency anemia.
Pregnant women also are at higher risk for the
condition because they need twice as much iron as usual. The extra iron is
needed for increased blood volume and for the fetus' growth.
About half of all pregnant women develop
iron-deficiency anemia. The condition can increase a pregnant woman's risk for
a premature or low-birth-weight baby.
Adults Who Have Internal Bleeding
Adults who have internal bleeding, such as
intestinal bleeding, can develop iron-deficiency anemia due to blood loss.
Certain conditions, such as colon cancer and bleeding ulcers, can cause blood
loss. Certain medicines, such as aspirin, also can cause internal bleeding.
Other At-Risk Groups
People who get kidney dialysis treatment may develop
iron-deficiency anemia. This is because blood is lost during dialysis. Also,
the kidneys are no longer able to make enough of a hormone needed to make red
blood cells.
Certain eating patterns or habits can put you at
higher risk for iron-deficiency anemia. This can happen if you:
- Follow a diet that excludes meat and fish, which
are the best sources of iron. However, vegetarian diets can provide enough iron
if the right foods are eaten. For example, good nonmeat sources of iron include
spinach and other dark green leafy vegetables, certain types of beans, dried
fruits, and iron-fortified breads and cereals.
- Eat poorly due to money, social, health, or other
problems.
- Follow a very low-fat diet over a long period.
Some higher fat foods, like meat, are some of the best sources of iron.
- Follow a high-fiber diet. Large amounts of fiber
can slow the absorption of iron.
What Are the Signs and Symptoms of Iron-Deficiency
Anemia?
The signs and symptoms of iron-deficiency anemia
depend on how serious the condition is. Mild to moderate iron-deficiency anemia
may have no signs or symptoms.
When signs and symptoms do occur, they can range
from mild to severe. Many of the signs and symptoms of iron-deficiency anemia
apply to all types of
anemia.
Signs and Symptoms of Anemia
The most common symptom of all types of anemia is
fatigue (tiredness). Not having enough hemoglobin in the blood causes fatigue.
Hemoglobin is an iron-rich protein in red blood cells that carries oxygen to
the body.
Anemia also can cause shortness of breath;
dizziness, especially when standing up; headache; coldness in your hands or
feet; pale skin, gums, and nail beds; and chest pain.
If you don't have enough hemoglobin-carrying red
blood cells, your heart has to work harder to circulate the reduced amount of
oxygen in your blood. This can lead to
arrhythmia,
heart
murmur, an enlarged heart, or even
heart
failure.
In infants and young children, signs of anemia
include poor appetite, slowed growth and development, and behavioral
problems.
Signs and Symptoms of Iron-Deficiency Anemia
Signs and symptoms of iron-deficiency anemia may
include brittle nails, swelling or soreness of the tongue, cracks in the sides
of the mouth, an enlarged spleen, and frequent infections.
People who have iron-deficiency anemia may have
unusual cravings for nonfood items such as ice, dirt, paint, or starch. This
craving is called pica (PI-ka or PE-ka).
Some people who have iron-deficiency anemia develop
restless
legs syndrome (RLS). RLS is a disorder that causes a strong urge to move
your legs. This urge to move often occurs with strange and unpleasant feelings
in your legs. People who have RLS often have a hard time sleeping.
Iron-deficiency anemia can put children at greater
risk for lead poisoning and infections.
Some signs and symptoms of iron-deficiency anemia
are related to the condition's causes. For example, a sign of intestinal
bleeding can be bright red blood in the stools or black, tarry-looking
stools.
Very heavy menstrual bleeding, long periods, or
other vaginal bleeding may suggest that a woman is at risk for iron-deficiency
anemia.
How Is Iron-Deficiency Anemia Diagnosed?
Your doctor will diagnose iron-deficiency anemia
based on your medical history, a physical exam, and the results from tests and
procedures.
Once your doctor knows the cause and severity of the
condition, he or she can create a treatment plan for you.
Mild to moderate iron-deficiency anemia may have no
signs or symptoms. Thus, you may not know you have it unless your doctor
discovers it from a screening test or while checking for other problems.
Specialists Involved
Primary care doctors often diagnose and treat
iron-deficiency anemia. These doctors include pediatricians, family doctors,
gynecologists/obstetricians, and internal medicine specialists.
A hematologist (a blood disease specialist), a
gastroenterologist (a digestive system specialist), and other specialists also
may help treat iron-deficiency anemia.
Medical History
To learn about your medical history, your doctor
will ask about your signs and symptoms and any past problems you’ve had
with
anemia
or low iron.
Your doctor also may ask about your diet and whether
you’re taking any medicines. If you're a woman, your doctor may ask
whether you could be pregnant.
Physical Exam
Your doctor will do a physical exam to look for
signs of iron-deficiency anemia. He or she may:
- Look at your skin, gums, and nail beds to see
whether they're pale or yellowish
- Listen to your heart for a rapid or irregular
heartbeat
- Listen to your lungs for rapid or uneven
breathing
- Feel your abdomen to check the size of your liver
and spleen
- Do a pelvic and rectal exam to check for internal
bleeding
Diagnostic Tests and Procedures
A number of tests and procedures are used to
diagnose iron-deficiency anemia. They can help confirm a diagnosis, look for a
cause, and find out how severe the condition is.
Complete Blood Count
Often, the first test used to diagnose anemia is a
complete
blood count (CBC). The CBC measures many different parts of your blood.
This test checks your hemoglobin and hematocrit
(hee-MAT-oh-crit) levels. Hemoglobin is the iron-rich protein in red blood
cells that carries oxygen to the body. Hematocrit is a measure of how much
space red blood cells take up in your blood. A low level of hemoglobin or
hematocrit is a sign of anemia.
The normal range of these levels varies in certain
racial and ethnic populations. Your doctor can explain your test results to
you.
The CBC also checks the number of red blood cells,
white blood cells, and platelets in your blood. Abnormal results may be a sign
of infection, a blood disorder, or another condition.
Finally, the CBC looks at mean corpuscular
(kor-PUS-kyu-lar) volume (MCV). MCV is a measure of the average size of your
red blood cells. The results may be a clue as to the cause of your anemia. In
iron-deficiency anemia, for example, red blood cells usually are smaller than
normal.
Other Blood Tests
If the CBC results confirm you have anemia, you may
need other blood tests to find out what's causing the condition, how severe it
is, and the best way to treat it.
A reticulocyte (re-TIK-u-lo-site) count measures the
number of young red blood cells in your blood. The test shows whether your bone
marrow is making red blood cells at the correct rate.
Your doctor also may order a peripheral smear. For
this test, a sample of your blood is examined under a microscope. In people who
have iron-deficiency anemia, the red blood cells will look smaller and paler
than normal.
Your doctor may recommend tests to measure iron
levels in your blood and body. These tests can show how much iron has been used
from your body's stored iron. These tests include:
- Serum iron. This test measures the amount of iron
in your blood. The level of iron in your blood may be normal even if the total
amount of iron in your body is low. For this reason, other iron tests also are
done.
- Serum ferritin. Ferritin is a protein that helps
store iron in your body. A measure of this protein helps your doctor find out
how much of your body's stored iron has been used up.
- Transferrin level, or total iron-binding
capacity. Transferrin is a protein that carries iron in your blood. Total
iron-binding capacity measures how much of the transferrin in your blood isn't
carrying iron. If you have iron-deficiency anemia, you'll have a high level of
transferrin that has no iron.
Your doctor also may recommend tests to check your
hormone levels, especially your thyroid hormone. You also may have a blood test
for a chemical called erythrocyte protoporphyrin. This chemical is a building
block for hemoglobin.
Tests and Procedures for Gastrointestinal Blood
Loss
To check whether internal bleeding is causing your
iron-deficiency anemia, your doctor may suggest a fecal occult blood test. This
test looks for blood in the stools and can detect bleeding in the intestines.
If the test finds blood, you may have other tests
and procedures to find the exact spot of the bleeding. These tests and
procedures may look for bleeding in the stomach, upper intestines, and colon or
pelvic organs.
How Is Iron-Deficiency Anemia Treated?
Treatment for iron-deficiency anemia will depend on
the cause and severity of the condition. Treatments may include dietary changes
and supplements, medicines, and surgery.
Severe iron-deficiency anemia may require treatment
in a hospital,
blood
transfusions, iron injections, or intravenous (IV) iron therapy.
The goals of treating iron-deficiency anemia are to
treat its underlying cause and restore normal levels of red blood cells,
hemoglobin, and iron.
Dietary Changes and Supplements
Iron
You may need iron supplements to build up your iron
levels as quickly as possible. Iron supplements can correct low iron levels
within months. Supplements come in pill form or in drops for children.
Large amounts of iron can be harmful. Thus, you
should take iron supplements only as your doctor prescribes. Keep iron
supplements out of reach from children. This will prevent them from taking an
overdose of iron.
Iron supplements can cause side effects, such as
dark stools, stomach irritation, and heartburn. Iron also can cause
constipation, so your doctor may suggest that you use a stool softener.
Your doctor may advise you to eat more foods that
are rich in iron. The best source of iron is red meat, especially beef and
liver. Chicken, turkey, pork, fish, and shellfish also are good sources of
iron.
The body tends to absorb the iron from meat better
than iron in other foods. However, other foods also can help you raise your
iron levels.
Nonmeat foods that are good sources of iron
include:
- Spinach and other dark green leafy
vegetables
- Peanuts, peanut butter, and almonds
- Eggs
- Peas; lentils; and white, red, and baked beans
- Dried fruits, such as raisins, apricots, and
peaches
- Prune juice
Iron is added to some foods, such as cereal, bread,
and pasta. You can look at the Nutrition Facts label on a food to find out how
much iron it contains. The amount is given as a percentage of the total amount
of iron you need every day.
Vitamin C
Vitamin C helps the body absorb iron. Good sources
of vitamin C are fruits and vegetables, especially guava, red sweet pepper,
kiwi, oranges and orange juice, green pepper, and grapefruit juice.
If you're taking medicines, ask your doctor or
pharmacist whether you can eat grapefruit or drink grapefruit juice. This fruit
can affect the strength of a few medicines and how well they work.
Other fruits rich in vitamin C are strawberries,
cantaloupe, papaya, pineapple, and mango. Vegetables high in vitamin C include
vegetable and tomato juices, Brussels sprouts, kohlrabi, broccoli, sweet
potato, cauliflower, and kale.
Fresh and frozen fruits, vegetables, and juices
usually have more vitamin C than canned ones.
Treatment To Stop Bleeding
If blood loss is causing iron-deficiency anemia,
treatment will depend on the cause of the bleeding. For example, if you have a
bleeding ulcer, your doctor may prescribe antibiotics and other medicines to
treat the ulcer.
If your blood loss is due to a polyp or a cancerous
tumor in your intestine, you may need surgery to remove the growth.
If blood loss is due to heavy menstrual flow, your
doctor may prescribe oral contraceptives to help reduce your monthly blood
flow. In some cases, surgery may be advised.
Treatments for Severe Iron-Deficiency Anemia
If your iron-deficiency anemia is severe, you may
get a transfusion of red blood cells. A blood transfusion is a safe, common
procedure in which blood is given to you through an IV line in one of your
blood vessels. Transfusions require careful matching of donated blood with the
recipient's blood.
A transfusion of red blood cells will treat your
anemia right away. The red blood cells also give a source of iron that your
body can reuse. However, transfusions are only a short-term treatment. Your
doctor will need to find and treat the cause of your anemia.
Iron also may be injected into a muscle or through
an IV tube into a vein. However, IV iron therapy presents some safety concerns.
It must be done in a hospital or clinical setting by experienced staff. This
therapy usually is given to people who need iron long-term but can’t take
iron supplements by mouth or who need to be treated for iron-deficiency anemia
right away.
How Can Iron-Deficiency Anemia Be Prevented?
Eating a well-balanced diet that includes foods that
are good sources of iron may help you prevent iron-deficiency anemia. Taking
iron supplements (as your doctor prescribes) also may lower your risk for the
condition if you're not able to get enough iron from food.
For more information on diet and supplements, see
"How Is Iron-Deficiency Anemia Treated?"
Special measures can help prevent iron-deficiency
anemia in infants and young children and women—two groups at highest risk
for the condition.
Infants and Young Children
A baby's diet can affect his or her risk for
iron-deficiency anemia. For example, cow's milk is low in iron. For this and
other reasons, cow's milk is not recommended for babies in their first year.
After the first year, you may need to limit the amount of cow's milk your baby
drinks.
Also, babies need more iron as they grow and begin
to eat solid foods. Talk to your child’s doctor about a healthy diet and
food choices that will help your child get enough iron.
Your child's doctor may recommend iron drops.
However, giving a child too much iron can be dangerous. It's important to
follow the doctor's instructions and keep iron supplements and vitamins away
from children. Asking for child-proof packages for supplements can help prevent
overdosing in children.
Women
Women of childbearing age may be tested for
iron-deficiency anemia, especially if they have:
- A history of iron-deficiency anemia
- Heavy blood loss during their monthly
periods
- Other risk factors for iron-deficiency
anemia
For pregnant women, medical care during pregnancy
usually includes screening for anemia. Also, your doctor may prescribe an iron
supplement or advise you to eat more iron-rich foods.
Living With Iron-Deficiency Anemia
If you have iron-deficiency anemia, it’s
important to take care of your health. See your doctor regularly to make sure
your iron levels are improving. At your checkups, your doctor may change your
medicines or supplements. He or she also may suggest ways to improve your
diet.
Take iron supplements only with your doctor's
approval, and only as he or she prescribes. It’s possible to have too much
iron in your body (a condition called iron overload). Too much iron in your
body can damage your organs.
You may have fatigue (tiredness) and other symptoms
of iron-deficiency anemia until your iron levels return to normal. This can
take months. Tell your doctor if you get any new symptoms or if your symptoms
get worse.
Key Points
- Iron-deficiency anemia is a common, easily
treated condition that occurs when you don't have enough iron in your
body.
- Low iron levels usually are due to blood loss,
poor diet, or an inability to absorb enough iron from the foods you eat.
- Iron-deficiency anemia usually develops over time
if your body doesn't have enough iron to build healthy red blood cells. Without
enough iron, your body starts using the iron it has stored. After the stored
iron is gone, your body makes fewer red blood cells. The red blood cells it
does make will have less hemoglobin than normal. Hemoglobin is a protein that
helps carry oxygen to your body.
- People at highest risk for iron-deficiency anemia
include infants and young children, women of childbearing age, and adults who
have internal bleeding.
- The signs and symptoms of iron-deficiency anemia
depend on how serious the condition is. Mild to moderate iron-deficiency anemia
may have no signs or symptoms. Many of the signs and symptoms of
iron-deficiency anemia, such as fatigue (tiredness), apply to all types of
anemia.
- Your doctor will diagnose iron-deficiency anemia
based on your medical history, a physical exam, and the results from tests and
procedures.
- Treatment for iron-deficiency anemia will depend
on the cause and severity of the condition. Treatments may include dietary
changes and supplements, medicines, and surgery. Severe iron-deficiency anemia
may require treatment in a hospital,
blood
transfusions, iron injections, or intravenous iron therapy.
- Eating a well-balanced diet that includes foods
that are good sources of iron may help you prevent iron-deficiency anemia.
Taking iron supplements (as your doctor prescribes) also may lower your risk
for the condition if you're not able to get enough iron from food.
- If you have iron-deficiency anemia, it's
important to take care of your health. See your doctor regularly, take iron
supplements only as your doctor prescribes, and tell your doctor if you have
any new symptoms or if your symptoms get worse.
- Iron-deficiency anemia usually can be
successfully treated.
Links to Other Information About Iron-Deficiency
Anemia
NHLBI Resources
- Anemia
(Diseases and Conditions Index)
Non-NHLBI Resources
Clinical Trials
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