What Is Anemia?
Anemia happens when the number of healthy red blood cells in
your body is too low. Red blood cells carry oxygen to all of the body’s
tissues, so a low red blood cell count indicates that the amount of oxygen in
your blood is lower than it should be. Many of the symptoms of anemia are
caused by decreased oxygen delivery to the body’s vital tissues and organs.
Anemia is measured according to the amount of hemoglobin,
which is the protein within red blood cells that carries oxygen from the lungs
to the body’s tissues. According to the , about 3 million Americans suffer from anemia.
Women and people with chronic diseases such as cancer have the highest risk of developing
What Causes Anemia?
Dietary iron, vitamin B-12, and folate are essential for red
blood cells to mature in the body. Normally, 0.8 to 1 percent of the body’s red
blood cells are replaced every day and the average lifespan for red cells is
100 to 120 days. In general, any process that has a negative effect on this
balance between red blood cell production and destruction can cause anemia.
Causes of anemia are generally divided into those that decrease red blood cell production
and those that increase red blood cell destruction.
Factors that decrease red blood cell production include:
- inadequate stimulation of red blood cell
production by the hormone erythropoietin, which is produced by the kidneys
- inadequate dietary intake of iron, vitamin B-12,
On the other hand, any disorder that destroys red blood
cells at a rate that’s faster than they’re made can cause anemia. Factors that increase
red blood cell destruction include:
- hemorrhage from accidents, gastrointestinal
lesions, menstruation, childbirth, excessive uterine bleeding, or surgery
- cirrhosis, which involves scarring of the liver
- fibrosis, or scar tissue, within the bone marrow
- hemolysis, which is the rupture of red blood
cells that can occur with some medications or Rh incompatibility
- disorders of the liver and spleen
- genetic disorders such as glucose-6-phosphate
dehydrogenase (G6PD) deficiency, thalassemia, and sickle cell anemia
Overall, however, iron deficiency is the most common cause
of anemia. Iron intake is a major index for the health assessment of nations.
According to the , an estimated 2 billion people worldwide have
anemia, and many have it because of iron deficiency.
Daily Nutritional Requirements and Anemia
Daily requirements for vitamins and iron vary according to
sex and age. Women need more iron and folate than men because of iron losses
during their menstrual cycle and fetal development during pregnancy and
According to the , the recommended daily iron intake for women age 19
to 50 is 18 mg. The daily iron intake for men of the same age range is 8 mg.
During pregnancy, daily iron intake should increase to 27 mg, but women who are
breastfeeding only need 9 mg per day.
Men and women over the age of 50 require 8 mg of iron daily.
A supplement may be needed if adequate iron levels can’t be reached through
diet alone. Good sources of dietary iron include:
- chicken and beef liver
- dark turkey meat
- red meats, such as beef
- fortified cereals
Folate is the form of folic acid that occurs naturally in
the body. Males and females over the age of 14 require
(micrograms of dietary folate equivalents) per day. For women who are pregnant
or breastfeeding, the recommended intake increases to 600 mcg/DFE per day.
Examples of foods rich in folate are:
- beef liver
- great northern beans
You can also add folic acid to your diet with fortified
cereals and breads.
The daily adult recommendation for vitamin B-12 is . Women
and teens who are pregnant need 2.6 mcg per day, and women who are
breastfeeding require 2.8 mcg daily.
Beef liver and clams are two of the best sources of vitamin
B-12. Other good sources include:
- other dairy products
Vitamin B-12 is also available as a supplement for those who
don’t get enough from their diet alone.
What Are the Symptoms of Anemia?
People with anemia appear pale and may often complain of
being cold. They may also have lightheadedness or dizziness, especially when
they are active or standing up. Some people with anemia have unusual cravings
such as wanting to eat ice, clay, or dirt. They often complain of feeling tired
and have problems with constipation and concentration.
If anemia is severe, fainting may occur. Other symptoms
include brittle nails, shortness of breath, and chest pains. Blood oxygen
levels can be so low that a person with severe anemia can have a heart attack.
A physical exam that your doctor does may show:
- high or low blood pressure
- pale skin
- increased heart rate
- heart murmur
- enlarged lymph nodes
- enlarged spleen or liver
People with symptoms of anemia should seek medical
How Is Anemia Diagnosed?
A diagnosis of anemia begins with your family and health history
and a physical exam. Laboratory tests help doctors to find out the cause of the
anemia. A family history of certain types of anemia such as sickle cell anemia can
be helpful. A history of exposure to toxic agents in the home or workplace
might point to an environmental cause.
Tests to diagnose anemia include:
Complete Blood Count (CBC)
This blood test tells doctors the number and size of the
RBCs. It also shows if other blood cells like white blood cells and platelets
Serum Iron Levels
This blood tests shows if iron deficiency is the cause of
This blood test analyzes iron stores.
Vitamin B-12 Test
This blood test shows vitamin B-12 levels and determines if
they are too low.
This blood test reveals if serum folate levels are too low.
Stool Test for Occult Blood
This test applies a chemical to a stool specimen to see if
blood is present. If the test is positive, it means that blood is being lost
anywhere in the gastrointestinal tract, from the mouth to the rectum. Problems
like stomach ulcers, ulcerative colitis, and colon cancer can cause blood to be
Based on the results of these tests, doctors may order
additional studies such as an upper GI, a barium enema, chest X-rays, or a CT scan
of your abdomen.
How to Treat Anemia
The treatment for anemia depends on its cause. Anemia caused
by inadequate amounts of dietary iron, vitamin B-12, and folate is treated with
nutritional supplements. Your doctor and nutritionist can prescribe a diet that
contains proper amounts of vitamins, minerals, and other nutrients. A proper
diet can help prevent this kind of anemia from recurring.
In some cases, if the anemia is severe, doctors use
erythropoietin injections to increase red blood cell production in the bone
marrow. If bleeding occurs or the hemoglobin level is very low, a blood
transfusion may be necessary.
What Is the Outlook for Anemia?
The long-term outlook for anemia depends on the cause and
the response to treatment. Anemia is very treatable, but it can be dangerous if
it’s left untreated. Pay attention to food labels and invest in a multivitamin
to ensure that you’re getting the recommended daily amount of iron.
Talk to your doctor if you’re experiencing any of the
symptoms of anemia, especially if you have a family history of anemia. Your
doctor will most likely get you started on a diet or supplement regimen to
increase your iron intake. An iron deficiency may also be a sign of more
serious medical conditions, so it’s important to pay attention to your body. In
most cases, just tweaking your diet or taking an iron supplement can solve your