Microcytic anemia means that you have smaller red blood cells than typical and fewer of them. It can result from an iron deficiency or another health condition.
Microcytosis is a term used to describe red blood cells that are smaller than normal. Anemia is when you have low numbers of properly functioning red blood cells in your body.
In microcytic anemias, your body has fewer red blood cells than normal. The red blood cells it does have are also too small. Several different types of anemias can be described as microcytic.
Keep reading to learn about the symptoms, types, and causes of microcytic anemia and how doctors treat it.
You may not notice any symptoms of microcytic anemia at first. Symptoms often appear at an advanced stage when the lack of normal red blood cells is affecting your tissues.
Common symptoms of microcytic anemias include:
- fatigue, weakness, and tiredness
- loss of stamina
- shortness of breath
- dizziness
- pale skin
If you experience any of these symptoms and they don’t resolve within 2 weeks, make an appointment to see your doctor.
You should make an appointment to see your doctor as soon as possible if you experience severe dizziness or shortness of breath.
Microcytic anemias usually result from health conditions that prevent your body from producing enough hemoglobin. Hemoglobin is a component of your blood. It helps transport oxygen to your tissues and gives your red blood cells their red color.
Iron deficiency
Microcytic anemias can be further described according to the amount of hemoglobin in the red blood cells. They can be:
- Hypochromic: The red blood cells have less hemoglobin than normal, which makes them paler in color.
- Normochromic: The blood cells have a normal amount of hemoglobin.
- Hyperchromic: The red blood cells have more hemoglobin than normal, which makes them darker in color.
These types are then further classified:
Hypochromic microcytic anemias
In microcytic hypochromic anemia, your body has low levels of red blood cells that are both smaller and paler than normal.
Most microcytic anemias are hypochromic. They include:
Iron deficiency anemia
The
- inadequate iron intake, usually as a result of diet
- inability to absorb iron due to conditions like celiac disease or Helicobacter pylori infection
- chronic blood loss due to frequent or heavy periods in women or by gastrointestinal (GI) bleeds from upper GI ulcers or inflammatory bowel disease
- pregnancy
Thalassemia
Thalassemia is a type of anemia that’s caused by an inherited abnormality. It involves mutations in the genes needed for normal hemoglobin production.
Sideroblastic anemia
Sideroblastic anemia can be inherited due to gene mutations (congenital).
It can also happen if you develop a condition that negatively affects your body’s ability to integrate iron into one of the components needed to make hemoglobin. This results in a buildup of iron in your red blood cells.
Congenital sideroblastic anemia is usually microcytic and hypochromic.
Normochromic microcytic anemias
Normochromic means that your red blood cells have a normal amount of hemoglobin, and the hue of red is not too pale or deep in color. An example of a normochromic microcytic anemia is:
Anemia of inflammation and chronic disease
Anemia due to these conditions is usually normochromic and normocytic (red blood cells are normal in size). Normochromic microcytic anemia may be seen in people with:
- infectious diseases, such as tuberculosis, HIV, or endocarditis
- inflammatory diseases, such as rheumatoid arthritis, Crohn’s disease, or diabetes mellitus
- kidney disease
- cancer
These conditions can prevent red blood cells from functioning normally, leading to decreased iron absorption or utilization.
Hyperchromic microcytic anemias
Hyperchromic means that the red blood cells have more hemoglobin than normal. High levels of hemoglobin in your red blood cells make them a deeper hue of red.
Hemoglobin SC (HbSC) disease
SbSC disease is a form of sickle cell disease. It can cause symptoms similar to sickle cell disease, but they are typically less frequent. Some people with HbSC may have hemoglobin levels that are almost normal levels. It
Other causes of microcytic anemia
Other causes of microcytic anemia include:
- lead toxicity
- copper deficiency
- zinc excess, which causes copper deficiency
- alcohol use
- drug use
Microcytic anemias are often first spotted after a doctor orders a blood test known as a complete blood count (CBC) for another reason. If your CBC indicates anemia, doctors may then order another test known as a peripheral blood smear.
This test can help spot changes in your red blood cells. The peripheral blood smear test may help identify the type of microcytic anemia.
A primary care doctor may refer you to a hematologist, a specialist who works with blood disorders. A hematologist can best diagnose and treat the specific type of microcytic anemia and identify its underlying cause.
Once a doctor has diagnosed microcytic anemia, they usually ask about your symptoms and order additional tests to determine the cause of the condition. This can include:
- additional blood tests for celiac disease
- blood and stool tests for H. pylori bacterial infection
They may also refer you to other specialists.
If you have stomach or other abdominal pain, they may refer you to a gastroenterologist, a doctor who specializes in the digestive system. A gastroenterologist may recommend imaging tests that may include:
- abdominal ultrasound
- upper GI endoscopy (EGD)
- CT scan of the abdomen
If you have heavy periods and pelvic pain, a gynecologist may look for uterine fibroids or other conditions that could cause heavier flows.
Treatment for microcytic anemia focuses on treating the underlying cause.
If you have iron deficiency anemia, a doctor may recommend taking iron and vitamin C supplements. Iron helps treat anemia while vitamin C helps improve your body’s ability to absorb iron.
If acute or chronic blood loss is causing or contributing to microcytic anemia, the doctor usually focuses on determining the cause. People with iron deficiency from severe periods may be prescribed hormonal therapy, such as birth control pills.
If your microcytic anemia is so severe that you’re at risk for complications like cardiac failure, you may need a blood transfusion. This can increase the number of healthy red blood cells your organs need.
Treatment can be relatively straightforward if simple nutrient deficiencies cause microcytic anemia. If the underlying cause can be treated, anemia can be treated and cured.
Very severe untreated microcytic anemia
- low blood pressure, also called hypotension
- coronary artery problems
- pulmonary problems
- shock
These complications are more common in older adults who already have pulmonary or cardiovascular diseases.
You can prevent some causes of microcytic anemia by getting enough iron in your diet. Increasing your vitamin C intake can also help your body absorb more iron.
You can also consider taking a daily iron supplement. These are often recommended if you already have anemia. You should always talk with a doctor before you start taking any supplements.
You can also try to get more nutrients through your food.
Foods rich in iron include:
- red meat like beef
- poultry
- dark leafy greens
- beans
- dried fruits like raisins and apricots
Foods rich in vitamin C include:
- citrus fruits, especially oranges and grapefruits
- kale
- red peppers
- Brussels sprouts
- strawberries
- broccoli
Microcytic anemia means that your red blood cells are smaller than normal and that there are fewer of them in your blood.
This type of anemia commonly results from not getting enough iron, but other health conditions can cause it.
Treating it usually involves treating the underlying cause.