Microcytic anemia is a condition in which the body’s tissues and organs do not get enough oxygen.

This lack of oxygen can happen because the body does not have enough red blood cells, or because the red blood cells do not contain enough hemoglobin, which is a protein that transports oxygen in the blood. When there is a lack of hemoglobin in a red blood cell, the cell is smaller in size and can carry less oxygen.

Microcytic anemia is not one condition, but rather describes several different types of anemia.

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Lack of oxygen in the body may be due to a lack of red blood cells.

Many people have no symptoms of microcytic anemia in its earlier stages. The American Academy of Family Physicians (AAFP) state that doctors discover it by chance when a person is having a blood test for another reason.

For those who have more severe anemia, symptoms may include:

  • pale skin that looks gray
  • pale color inside the eyelids or under the nails
  • weakness or tiredness
  • irritability
  • shortness of breath
  • rapid heart rate
  • pica, which is a desire to eat things such as ice, dirt, and clay
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Irritability, tiredness, and pale skin may be symptoms of severe anemia.

Microcytic anemia can be caused by several different health conditions, ranging from mild problems to more serious issues. It is important to work with a healthcare team to find the underlying cause.

An article in the International Journal of Laboratory Hematology states that microcytic anemia is usually caused by one of the following conditions whose names form the acronym TAILS:


Thalassemia is an inherited blood disorder that parents can pass down to their children as a result of abnormal genes.

If someone has thalassemia, their body does not make enough of a particular protein typically found in hemoglobin.

Without this protein, red blood cells will not form properly or work as well as they should. The lack of this protein causes anemia, which can range from mild to severe depending on how many genes are affected.

An article in The BMJ states that iron deficiency anemia and thalassemia are the most common causes of microcytic anemia. These two conditions may also occur together in some people.

Anemia of chronic disease

Certain chronic diseases and conditions can cause microcytic anemia. This is usually called anemia of inflammation and chronic disease (AI/CD).

Chronic infections or inflammation can interfere with the way the body processes iron. About one-fourth to one-third of these types of anemia are classified as microcytic.

Some of the conditions that can cause this type of anemia include:

Iron deficiency anemia

The AAFP states iron deficiency is the most common cause of microcytic anemia.

The reason behind iron deficiency often varies depending on a person’s age and sex.

In children, nutritional deficiencies are usually the cause of iron deficiency anemia.

In menstruating women, menstrual blood loss is the most common culprit for iron deficiency.

The most common reason for iron deficiency in adult men and nonmenstruating women is blood loss. Most commonly, this blood loss occurs in the gut, which may be the result of a bleeding ulcer in the stomach.

In some cases, a tumor in the gut can cause bleeding. Some people may need additional testing to look for a tumor or to rule it out.

Older adults may have iron deficiency anemia from because their diet lacks certain nutrients, or because they have particular chronic health conditions that hinder their body’s ability to absorb iron. An article in American Family Physician found that anemia prevalence ranges from 8-44 percent in older men.

Lead poisoning

Children who are exposed to lead-based paint because they live in an older home, or because it is on toys or other objects, can get lead poisoning when they put objects in their mouths.

Contaminated water and exposure to heavy industrial pollution can also cause lead poisoning, though this is less common.

Sideroblastic anemia

Congenital sideroblastic anemia is an inherited blood disorder that affects the bone marrow’s ability to produce red blood cells. Though it can cause microcytic anemia, it is less common than the other causes.

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A doctor may recommend iron supplements to treat anemia.

People that develop anemia of any type should see their doctor for treatment, even if no symptoms are present.

Although somebody who has mild anemia may feel fine, the condition can cause damage to critical organs in the body over time. Severe or long-lasting anemia can even cause death.

Treatment depends on the underlying cause of microcytic anemia. Doctors may need to carry out some tests to determine a cause so that they can put together a treatment plan.

Doctors may recommend iron supplements, which often resolve microcytic anemia in children. If they do not help, further tests may be needed to check for blood loss or another possible cause.

Other treatment options include:

  • antibiotics to treat chronic infections that are causing anemia
  • hormones to treat heavy menstrual bleeding
  • a medication that stimulates the body to make more red blood cells
  • blood transfusions (in more severe cases).
  • surgery to correct a bleeding stomach ulcer or a tumor in the gut

Chelation, which is a therapy that helps reduce lead levels in the body, may also be used. This therapy is sometimes helpful in children with anemia, because anemia makes them more likely to get lead poisoning.

In some cases, such as with an inherited disorder, there is no proven way to prevent microcytic anemia completely.

Eating a balanced diet high in iron, vitamin B12, vitamin C, and folic acid can be helpful for almost anyone with anemia.

People who do not get enough iron in their diets may need to take supplements under a doctor’s supervision.

The American Academy of Pediatrics says that infants should not be given cow’s milk especially before they are 12 months old. Giving cow’s milk to a child too early can cause blood loss in the stool and can interfere with iron absorption.

Parents should ask their pediatricians about the right age to introduce cow’s milk.

Breast-fed babies usually get enough iron from their mothers up to 4 months of age. Once the baby is ready for solid foods, introduce foods with added iron to their diet. Give formula-fed babies formula that has proper amounts of iron.

Children and cow’s milk

Older children can usually consume up to 2 cups of whole cow’s milk per day. Drinking more than this amount can lead to iron deficiency anemia.

Anemia can occur because:

  • milk is naturally low in iron
  • milk can fill a child up, leaving less room for iron-rich foods in the diet
  • milk contains calcium and casein, which interfere with the body’s ability to absorb iron

Good food sources of iron

People of all ages can benefit from iron-rich foods that can help prevent some types of anemia. Also, foods high in vitamin C, such as citrus fruits, help the body absorb iron better.

The body absorbs the animal form of iron most efficiently, so vegetarians may need to be more mindful of getting enough iron.

Some of the most common iron-rich foods include:

  • red meat
  • egg yolks
  • fortified grains and cereals
  • beans
  • leafy, green vegetables
  • tomatoes
  • potatoes
  • raisins

The long-term outlook for people with microcytic anemia depends largely upon the cause of the anemia. Most cases are mild, particularly those that are caused by a slight iron deficiency.

More severe forms or those caused by thalassemia, ulcers, or tumors may require more medical care.

The key to a higher quality of life with microcytic anemia is to identify it and treat it as soon as possible.

Getting regular complete blood counts (CBCs) can help diagnose anemia in those who have no symptoms. This leads to earlier treatment of the underlying cause and usually a better quality of life overall.