General Practice 2022

7 main causes of anemia

Table of contents:

7 main causes of anemia
7 main causes of anemia

Anemia is characterized by decreased levels of hemoglobin in the blood, which is a protein that is inside red blood cells and is responsible for carrying oxygen to the organs.

There are several causes for anemia, from a diet low in vitamins to bleeding, bone marrow malfunction, autoimmune diseases or the existence of chronic diseases, for example.

Anemia can be mild or even profound, when the hemoglobin level is below 7%, and this not only depends on the cause, but also on the severity of the disease and the response of each person's organism.

Some of the main causes of anemia include:

1. Vitamin deficiency

To properly produce red blood cells, the body needs essential nutrients. The lack of them causes the so-called deficiency anemias, which are;

  • Anemia due to lack of iron in the body, called iron deficiency anemia, which can arise from a diet with little iron, especially in childhood, or due to bleeding in the body, which can be imperceptible, such as a gastric ulcer or varicose veins in the intestine, for example;
  • Anemia due to lack of vitamin B12 and folic acid, called megaloblastic anemia, occurs due to malabsorption of vitamin B12 mainly in the stomach and low consumption of folic acid in food. Vitamin B12 is consumed in meat or animal derivatives such as eggs, cheese and milk. Folic acid is found in meats, green vegetables, beans or grains, for example.

The absence of these nutrients is detected through blood tests ordered by the doctor. Generally, this type of anemia gets worse gradually, and as the body can adapt to losses for some time, symptoms may take time to appear.

Watch the video below and check out nutritionist Tatiana Zanin's guidelines on what to eat in case of anemia:

2. Bone marrow defects

The bone marrow is where blood cells are produced, so if it is affected by any disease, it can compromise the formation of red blood cells and cause anemia.

This type of anemia, also called Aplastic anemia or Medullary anemia, can have several causes, which include genetic defects, poisoning by chemical agents such as solvents, bismuth, pesticides, tar, anticonvulsants, exposure to ionizing radiation, infections by HIV, parvovirus B19, Epstein-Barr virus or by diseases such as paroxysmal nocturnal hemoglobinuria, for example. However, in some rare cases, the cause may not be identified.

Read more about what it is and what to do in case of aplastic anemia.

3. Hemorrhages

Bleeding is serious as blood loss represents the loss of red blood cells and, consequently, a decrease in the amount of oxygen and nutrients transported to the organs of the body.

Some of the most common causes of bleeding can be caused by injuries to the body, trauma from accidents, heavy menstruation or diseases such as cancer, liver disease, varicose veins or ulcers, for example.

In some cases, the bleeding is internal and, therefore, is not visible, requiring examinations to identify it. Check out the main causes of internal bleeding.

4. Genetic diseases

Hereditary diseases, which are passed through the DNA, can cause changes in the production of hemoglobin, either in its quantity or in its quality. These changes usually result in red blood cell destruction.

Not always the carrier of these genetic defects will present a worrisome anemia, however, in some cases it can be serious and significantly compromise he alth. The main anemias of genetic origin are those that affect the structure of hemoglobin, also called hemoglobinopathies:

  • Sickle cell anemia: it is a genetic and hereditary disease in which the organism produces hemoglobin with an altered structure, therefore, it originates defective red blood cells, which can assume the shape of a sickle, making it difficult to its ability to carry oxygen in the blood. Check out the symptoms and treatment of sickle cell anemia.
  • Thalassaemia: it is also a genetic disease that causes changes in the proteins that form hemoglobin, forming altered red blood cells that are destroyed in the bloodstream. There are different types of thalassemia, with varying severity, learn more about how to identify thalassemia.

Although these are the best known, there are hundreds of other hemoglobin defects that can result in anemia, such as methemoglobinemia, unstable hemoglobins or hereditary persistence of fetal hemoglobin, for example, which are identified by genetic tests indicated by the hematologist.

5. Autoimmune diseases

Autoimmune hemolytic anemia (AIHA) is an immunological disease that arises when the body produces antibodies that attack its own red blood cells.

Although their exact causes are not yet known, it is known that they can be precipitated by other he alth conditions, such as viral infections, the presence of other immune diseases or tumors, for example. This type of anemia is not usually hereditary and is not transmissible from one person to another.

Treatment mainly consists of the use of medications to regulate the immune system, such as steroids and immunosuppressants. Learn more about identifying and treating autoimmune hemolytic anemia.

6. Chronic diseases

Chronic diseases, which are those that can last many months or years in activity, such as tuberculosis, rheumatoid arthritis, rheumatic fever, osteomyelitis, Crohn's disease or multiple myeloma, for example, cause an inflammatory reaction in the body that can result in anemia, due to premature death and changes in red blood cell production.

In addition, disease that causes changes in hormones that stimulate red blood cell production can also be the cause of anemia, including hypothyroidism, reduced androgens, or decreased levels of the hormone erythropoietin, which can be reduced in kidney disease.

This type of alteration does not usually cause severe anemia, and can be resolved with the treatment of the disease that caused the anemia.

7. Other causes

Anemia can also arise due to infections, as in viral or bacterial infections, as well as due to the use of certain medications, such as anti-inflammatories, antibiotics or anticoagulants, or the action of substances such as alcohol on excess or benzenes, for example.

Pregnancy can cause anemia, basically due to weight gain and increased fluid in the circulation, which thins the blood.

How to confirm if you have anemia

Usually anemia can be suspected when symptoms such as:

  • Excessive fatigue;
  • Too much sleep;
  • Pale skin;
  • Lack of strength;
  • Feeling short of breath;
  • Cold feet and hands.

To know the risk of having anemia, just mark the symptoms you are presenting in the following test:

  1. 1.Lack of energy and excessive tiredness Yes No
  2. 2.Pale skin Yes No
  3. 3.Lack of disposition and low productivity Yes No
  4. 4.Constant headache Yes No
  5. 5.Easy irritability Yes No
  6. 6.Inexplicable urge to eat something strange like brick or clay Yes No
  7. 7.Memory loss or difficulty concentrating Yes No


Make an appointment with a specialist

However, to confirm the diagnosis of anemia it is necessary to go to the doctor and have a blood test to evaluate the hemoglobin levels, which must be above 13% in men, 12% in women and 11% in pregnant women from the second trimester. Learn more about tests that confirm anemia.

If the hemoglobin values ​​of the blood test are below normal, the person is considered to have anemia. However, further tests may be necessary to identify the cause and initiate treatment, especially if there is no apparent reason for the onset of anemia.

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