What is anemia?

Anemia happens when you do not have enough red blood cells. The cells travel with iron and hemoglobin, which is a protein that helps carry oxygen through the bloodstream to your organs all through the body. When someone develops anemia, they are said to be "anemic." Being anemic might mean that you feel more tired or cold than you usually do, or if your skin seems too pale. This is due to your organs not receiving the oxygen they need to do their jobs. Some people find out they are low in iron when they go to donate blood.

Are there different kinds of anemia?

There are several different types of anemia, but each of them causes the number of red blood cells in circulation to drop. Red blood cell levels are low due to one of the following reasons:

  • Your body cannot make enough hemoglobin (low hemoglobin).
  • Your body makes hemoglobin, but the hemoglobin doesn't work correctly.
  • Your body does not make enough red blood cells.
  • Your body breaks down red blood cells too quickly.

Some types of anemia that you may have heard of include iron-deficiency anemia and sickle cell anemia.

How common is anemia?

Anemia affects more than two billion people globally, which is more than 30% of the total population. It is especially common in countries with few resources, but it also affects many people in the industrialized world. Within the U.S., anemia is the most common blood condition. An estimated three million Americans have the disorder.

Who is most likely to develop anemia?

Anyone can develop anemia, although the following groups have a higher risk:

  • Women: Blood loss during monthly periods and childbirth can lead to anemia. This is especially true if you have heavy periods or a condition like fibroids.
  • Children, ages 1 to 2: The body needs more iron during growth spurts.
  • Infants: Infants may get less iron when they are weaned from breast milk or formula to solid food. Iron from solid food is not as easily taken up by the body.
  • People over 65: People over 65 are more likely to have iron-poor diets and certain chronic diseases.
  • People on blood thinners: These medications include drugs include aspirin, clopidogrel (Plavix®), warfarin (Coumadin®), heparin products, apixaban (Eliquis®), betrixaban (BevyxXa®), dabigatran (Pradaxa®), edoxaban (Savaysa®) and rivaroxaban (Xarelto®).

What are the signs and symptoms of anemia?

Several signs and symptoms occur in all types of anemia, such as fatigue, shortness of breath and feeling cold. Others include:

  • Dizziness or weakness.
  • Headache.
  • Sore tongue.
  • Pale skin, dry skin, or easily bruised skin.
  • Unintended movement in the lower leg (restless legs syndrome).
  • Fast heartbeat.

How does anemia affect the body?

Anemia can have other affects on your body in addition to feeling tired or cold. Other signs that you might be lacking in iron include having brittle or spoon-shaped nails and possible hair loss. You might find that your sense of taste has changed, or you might experience ringing in your ears.

Different types of anemia may lead to other serious problems. People with sickle cell anemia often have heart and lung complications.

If you have anemia that is not treated, it could lead to an arrhythmia (irregular heartbeat), an enlarged heart or heart failure. You are also at greater risk of getting infections and becoming depressed.

You might have heard that iron deficiency is linked to chewing ice, which does happen. Chewing ice is a sign of pica, a condition that includes eating things that are not really food, like chalk or dirt. So pica is also a sign of iron deficiency. It is often seen in children with anemia.

How else does anemia affect children?

It is important for children to have enough iron and other nutrients in their diets to prevent anemia and the related problems with lack of attention, delayed development of motor skills and problems with learning. In older children, you need to pay more attention to signs of anemia during growth spurts and menstrual cycles.

How does anemia affect older adults?

In older adults, anemia might have even more impact in causing confusion or depression. Weakness may make walking more difficult. Anemia may shorten your lifespan if you are older and it is not treated.

Can anemia affect my weight?

Having enough iron may also be a factor in weight issues. Studies have found overweight people might lose weight if they address low iron in the blood. You might experience unintentional weight loss along with anemia if you have other conditions, such as cancer. People who have had weight loss surgery might become anemic due to vitamin and mineral deficiencies.

How does anemia affect pregnancy?

Iron deficiency during pregnancy increases the chance of complications, such as premature birth. After the birth, studies have indicated that babies born to women with low iron levels have a higher risk of low birth weight and problems with their own iron levels.

If you are pregnant, you are more likely to develop iron-deficiency anemia. Your unborn baby relies on you for iron and other nutrients. Many women who are pregnant take iron pills to prevent anemia. To make sure that you have enough iron for you and your baby, eat well-balanced meals that include iron-rich foods and foods that provide B12 and B9 vitamins. Follow your healthcare provider's instructions for taking vitamins and adding iron to your diet.

Finding out that you have anemia is just the beginning. Finding the cause of the anemia will lead you to the best treatment.

What causes anemia?

The most common cause of anemia is low levels of iron in the body. This type of anemia is called iron-deficiency anemia. Your body needs a certain amount of iron to make hemoglobin, the substance that moves oxygen throughout your body. However, iron-deficiency anemia is just one type. Other types are caused by:

  • Diets lacking in vitamin B12, or you can’t use or absorb Vitamin B12 (like pernicious anemia).
  • Diets lacking in folic acid, also called folate, or your body can’t use folic acid correctly (like folate-deficiency anemia).
  • Inherited blood disorders (like sickle cell anemia or thalassemia).
  • Conditions that cause red blood cells to break down too fast (like hemolytic anemia).
  • Chronic conditions causing your body to not have enough hormones to create red blood cells. These include hyperthyroidism, hypothyroidism, advanced kidney disease, lupus and other long-term diseases.
  • Blood loss related to other conditions such as ulcers, hemorrhoids or gastritis.

What causes iron-deficiency anemia?

You can get iron-deficiency anemia from:

  • Bleeding, either from losing a large amount of blood quickly (for instance, in a serious accident) or losing small amounts of blood over a long period of time. The body loses more iron with blood loss than it is able to replace with food. This can happen to women having heavy menstrual periods or in people who have inflammatory bowel disease.
  • Not getting enough iron in the diet.
  • Needing more iron than you did previously (for instance, during pregnancy or illness).

Some types of iron-deficiency anemia are called by other names related to the cause, such as anemia of chronic disease (also called anemia of inflammation) or acute blood loss anemia.

Other types of anemia

Pernicious anemia

In a strict sense, pernicious anemia happens when a person lacks something called intrinsic factor, which lets them absorb vitamin B12. Without vitamin B12, the body cannot develop healthy red blood cells. Other types of anemia that involve lack of B vitamins, such as B9 (folic acid), are also often lumped in as pernicious anemia. This name may refer to other conditions, including folic acid deficiency anemia and Addison’s anemia, even though there is no intrinsic factor deficiency.

Hemolytic anemia

This type of anemia can be caused by inherited or acquired diseases that cause the body to make deformed red blood cells that die off too quickly. (An acquired disease is one that you didn’t have when you were born.) If it is not genetic, hemolytic anemia can be caused by harmful substances or reactions to certain drugs.

Sickle cell anemia

This genetic form of anemia happens because the shape of the red blood cells is faulty. They are sickle shaped, which means that they can clog the blood vessels and cause damage. The hemoglobin does not work correctly. This type of anemia is most often, but not always, found in African Americans.

Diamond-Blackfan anemia

This is a rare blood disorder that may be inherited or acquired. In this type of anemia, the bone marrow does not make enough red blood cells. Diamond-Blackfan anemia is diagnosed within the first year of life in nearly 90% of people who have it.

Aplastic anemia

This is a type of anemia in that is caused by damaged bone marrow which is unable to make enough red blood cells. It also may be congenital or acquired. Another name for aplastic anemia is bone marrow aplasia (failure). Some people might think of this condition as cancer, but it is not.

There is something referred to by some people as myelodysplastic anemia. However, myelodyplastic syndromes (MDS) refer to actual cancer and are a result of abnormal cells in the bone marrow.

Fanconi anemia

This type of anemia is also rare and it is genetic. It happens because the bone marrow does not make enough red blood cells. There are physical signs of this condition, such as abnormal bone structure and abnormal skin color. About 50% of people with this condition are diagnosed by the time that they turn 10 years old.

Mediterranean anemia

This condition is also known as Cooley’s anemia and actually refers to beta thalassemia major. Thalassemias are inherited conditions in which your body does not make the right amount of hemoglobin. In addition to not making enough of these cells, the red blood cells do not live as long as they would in someone without the condition.

Vegetarian or vegan anemia

This term refers to the idea that people who are vegetarians or vegans have a difficult time getting enough iron because they don’t eat meat, poultry or seafood. However, careful food planning makes this statement false. There are plenty of ways to get enough iron with a plant-based diet.

Your healthcare provider might also use terms for anemia that refer to the size of the red blood cells. These words include terms like macrocytic anemia (larger than normal cells) or microcytic anemia (smaller than normal cells).

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