What Are Red Blood Cells?
Red blood cells play an important role in your health by carrying fresh oxygen throughout
Red blood cells are round with a flattish, indented center, like doughnuts without
a hole. Your healthcare provider can check on the size, shape, and health of your
red blood cells using tests, such as the complete blood count screening.
Red blood cells at work
Hemoglobin is the protein inside red blood cells that carries oxygen. Red blood cells
also remove carbon dioxide from your body, transporting it to the lungs for you to
Red blood cells are made inside your bones, in the bone marrow. They typically live
for about 120 days, and then they die.
Nutrition and red blood cells
Foods rich in iron help you maintain healthy red blood cells. Vitamins are also necessary
to build healthy red blood cells. These include vitamin E, found in foods such as
dark green vegetables, nuts and seeds, mango, and avocados; vitamins B2, B12, and
B3, found in foods such as eggs, whole grains, and bananas; and folate, available
in fortified cereals, dried beans and lentils, orange juice, and green leafy vegetables.
Illnesses of the red blood cells
Most people don't think about their red blood cells unless they have a disease that
affects these cells. Problems with red blood cells can be caused by illnesses or a
lack of iron or vitamins in your diet. Some diseases of the red blood cells are inherited.
Diseases of the red blood cells include many types of anemia, a condition in which
there are too few red blood cells to carry sufficient oxygen throughout the body.
People with anemia may have red blood cells that have an unusual shape or that look
normal, larger than normal, or smaller than normal.
Symptoms of anemia include tiredness, irregular heartbeats, pale skin, feeling cold,
and, in severe cases, heart failure. Children who don't have enough healthy red blood
cells grow and develop more slowly than other children. These symptoms demonstrate
how important red blood cells are to your daily life.
These are common types of anemia:
Iron-deficiency anemia. If you don't have enough iron in your body, your body won't be able to make enough
red blood cells. Iron-deficiency anemia is the most common form of anemia. Among the
causes of iron deficiency are a diet low in iron, a sudden loss of blood, a chronic
loss of blood (such as from heavy menstrual periods), or the inability to absorb enough
iron from food.
Sickle cell anemia. In this inherited disease, the red blood cells are shaped like half moons rather than
the normal indented circles. This change in shape can make the cells "sticky" and
unable to flow smoothly through blood vessels. This causes a blockage in blood flow.
This blockage may cause acute or chronic pain and can also lead to infection or organ
damage. Sickle cells die much more quickly than normal blood cells—in about 10 to
20 days instead of 120 days—causing a shortage of red blood cells.
Normocytic anemia. This type of anemia happens when your red blood cells are normal in shape and size,
but you don't have enough of them to meet your body's needs. Diseases that cause this
type of anemia are usually long-term conditions, like kidney disease, cancer, or rheumatoid
Hemolytic anemia. This type of anemia happens when red blood cells are destroyed by an abnormal process
in your body before their lifespan is over. As a result, your body doesn't have enough
red blood cells to function, and your bone marrow cannot make enough to keep up with
Fanconi anemia. This is a rare inherited disorder in which your bone marrow isn't able to make enough
of any of the components of blood, including red blood cells. Children born with this
disorder often have serious birth defects because of the problems with their blood
and may develop leukemia.