Anemia: types, causes, symptoms, treatments and what to eat


What is anemia?

Anemia is a symptom caused by the impairment of hemoglobin, a protein present in red blood cells, blood cells responsible for the transport of oxygen in the body. When these cells are below normal, the person is considered anemic.

This reduction in the number of red blood cells in the blood can happen due to the lack of one or more essential nutrients in the body, due to chronic, genetic, autoimmune diseases and other pathologies.

The most common anemia is iron deficiency anemia , caused by iron deficiency. It is estimated that more than 90% of anemias are caused by deficiency of this nutrient. It is essential for the production of hemoglobins, aiding in the transport of oxygen.

In addition to iron deficiency, anemia can also occur due to low intake of vitamin B12 and B9.

This condition can be more prevalent in children, pregnant women, adult women, adolescents and lactating women. However, men (adults or teenagers) and the elderly are also affected.

The most common signs of anemia involve feeling tired , unwell, lack of appetite and pallor. In children, a warning sign is apathy and learning disabilities.

In some types of anemia, such as pernicious, prevention is not possible, but there are ways of treatment and cure.

  1. What is anemia?
  2. Acute and chronic anemia
  3. Types of anemia
  4. What causes anemia?
  5. Risk factors
  6. Symptoms of anemia
  7. Diagnosis
  8. Exams
  9. Can anemia be cured?
  10. Treatments
  11. Medicines
  12. Prognosis
  13. Complications
  14. How to prevent?

Acute and chronic anemia

Acute anemia is a condition that sets in quickly. It is often caused by bleeding, when there is a large reduction in the body’s blood volume, even when the drop in hemoglobin (protein present in red blood cells) is not high.

It can occur in situations where the patient has an accident, gastrointestinal bleeding and surgery, for example. This would be a form of acquired anemia .

An acute drop, which can vary between 14g / dL and 10g / dL, is enough to cause many of the main symptoms of anemia.

On the other hand, anemias that settle in a slow and gradual (chronic) manner, in which there is a low production of hemoglobin over weeks or months, tend to be asymptomatic until well advanced stages.

With the slow process, existing hemoglobins have time to adapt, becoming more effective in capturing and distributing oxygen throughout the body (compensating for their low concentration in the body).

In these cases, due to the adaptability of red blood cells (red blood cells), patients with chronic anemia generally do not show symptoms up to levels of 8g / dL or 9g / dL of hemoglobin.

Chronic anemia, therefore, can be considered a type of hereditary or acquired anemia , as it also occurs due to nutritional insufficiency, iron deficiency, pregnancy and vitamin B12 and B9 deficiency.

Types of anemia

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Anemia can be understood through the classification made according to the size of the red blood cells, called mean corpuscular volume (CMV). The VCM has three divisions of anemia:

  • Macrocytic anemia : condition in which the red blood cells are larger than normal, as in the case of the megaloblastic type;
  • Microcytic anemia : when the red blood cells are smaller than normal;
  • Normocytic anemia : in this type of anemia, red blood cells do not show changes in size, a sudden loss of blood being characteristic of this condition, as in hemorrhages, for example.

But anemias can also be divided into some types depending on the cause:

Iron deficiency anemia (iron deficiency)

Iron deficiency anemia is caused by the lack of iron in the body, a fundamental nutrient for the performance of several basic functions of the body.

Hemoglobin, the main component of red blood cells, is a protein that needs iron to form, and is also responsible for transporting oxygen to the body. Thus, when iron deficiency occurs, there is a lack of raw material, so to speak, so that these red blood cells are produced and perform their function.

Therefore, whenever the body’s iron stores are very low, iron deficiency anemia or iron deficiency anemia develops.

Many factors can cause this deficiency, such as inadequate nutrition, bleeding, heavy menstruation or malabsorption of iron by the body.

In pregnant women, due to the increase in the amount of iron needed during this period, this type of anemia can also occur.

Sickle Cell Anemia

It is a genetic and hereditary anemia, also known as sickle-cell anemia . It happens due to a change in chromosome 11 (a structure that carries DNA). For this type of anemia to occur, 2 defective genes are needed.

In these cases, normally, the mother and father are carriers, each carrying a defective gene, but without manifestation of the disease or symptoms. However, upon receiving this genetic inheritance from the parents, the child receives the genetic combination (that is, 2 genes) to develop the condition.

When the patient has only 1 defective gene, he is identified only as having a sickle cell trait.

In this type of disease, the red blood cells are sickle-shaped, when they should normally have a more rounded shape.

Because of this variation in shape, blood cells have greater difficulty in carrying out the transport of oxygen in the required amount.

In addition, these sickle cells have a shorter duration than normal red blood cells and do not survive for long. The bone marrow, responsible for producing these cells, on the other hand, cannot keep up with the rhythm.

Therefore, the blood system is damaged. Without this replacement, several complications can happen, such as strokes, since red blood cells are responsible for the transport of oxygen and its absence can cause the death of tissues.

There are some factors that can trigger a sickling crisis, such as stress , fever and other infections. This crisis is characterized by the manifestation of symptoms such as severe pain in the bones, in the thoracic and abdominal region.

However, sickle cell anemia can still have great clinical variability, that is, it manifests itself severely in some patients – which can lead to more serious and frequent complications – or represent a mild and even asymptomatic clinical condition.

The diagnosis occurs right at birth, in the heel prick test . The treatment must be done since then, with the accompaniment of a medical board.

In some cases, bone marrow transplantation may be necessary during treatment to be able to replace the marrow that is unable to produce healthy red blood cells.

This type of anemia is more common in people of North African and Mediterranean populations. In Brazil, it is much more common in the black population.

Megaloblastic anemia

Megaloblastic anemia occurs when red blood cells (red blood cells) are larger than normal, as the cytoplasm does not divide properly, usually due to the lack of necessary nutrients, due to a deficiency of vitamin B12 or vitamin B9 ( folic acid )

In addition to the variation in size, they are also less resistant and end up dying before the expected time.

This type of anemia is installed in the individual’s body due to the damage that the deficiency of these vitamins causes, because without them the body is not able to correctly perform the synthesis of thymine.

Thus, chromosomes are unable to duplicate and there is no cell division process (mitosis).

People with this condition may experience symptoms such as stomachache, tiredness, hair loss, mouth sores, in addition to the common symptoms of anemia, such as dizziness , weakness, dryness of the mucous membranes and pallor.

Pernicious anemia

The pernicious anemia is a type of megaloblastic anemia, which occurs when there is the absence of intrinsic factor (a substance produced by the stomach that aids in the digestion of food and B12 absorption in the gut).

Without the vitamin, red blood cells are produced incorrectly, dying prematurely, configuring the anemic condition.

Autoimmune factors, overuse of antacids, bariatric surgery or gastric changes may be responsible for the manifestation of the pernicious type.

Hemolytic anemias

There are different forms of hemolytic anemia, but it is characterized by the difficulty of the bone marrow in producing red blood cells that, for different reasons, are being destroyed before the appropriate time.

This can happen due to certain infectious, autoimmune, genetic or hereditary diseases, such as hereditary spherocytosis (abnormal shape of red blood cells) and the deficiency of Glucose 6 Phosphate Dehydrogenase or G6PD (which facilitates the rupture of red blood cells), for example.

In the case of autoimmune hemolytic anemia, the patient’s own immune system understands red blood cells as invaders. Thus, they produce antibodies that attack and destroy them ahead of time.

In this type, treatment depends on the cause. In autoimmune manifestation, for example, treatment with drugs that inhibit the immune system may be necessary.

Anemia of the newborn

Newborns can also suffer from anemia. The main cause of this type of problem is a disease called fetal erythroblastosis , or Rh incompatibility.

Rh, or Rh factor, is an antigen present in the blood, which receives a positive or negative classification. When someone has the antigen naturally it is considered Rh + (positive). People who do not have this Rh factor naturally are classified as Rh- (negative).

When the baby’s positive Rh comes into contact with the mother’s negative Rh, the pregnant woman’s immune system may end up producing antibodies to defend herself against these antigens from the fetus, by understanding them as foreign bodies.

This defense system reaction is called Rh awareness .

Because of this conflict between the mother’s and baby’s antigens, the newborn can suffer from anemia, because antibodies can cross the placenta to the fetus, causing the destruction of red blood cells.

To defend against this anemia, the newborn’s body reacts by producing immature red blood cells, called erythroblasts. This is a condition that can pose serious risks to the baby’s health.

This Rh incompatibility rarely causes problems during the first pregnancy. However, by becoming more aware, the risks in future pregnancies are greater.

Anemia due to chronic diseases

It can be caused by the presence of autoimmune diseases , cancer , infectious diseases, chronic kidney failure and other pathologies such as HIV / AIDS , rheumatoid arthritis and Crohn’s disease .

Under these conditions, patients are at an increased risk of having a low production of red blood cells.

What is the cause of anemia?

Anemia occurs when hemoglobin levels in the blood, present in the transport of oxygen, are low. This reduction can be caused by vitamin B12 deficiency, iron deficiency, bone marrow problems, bleeding and genetic, hereditary, autoimmune and chronic diseases.

There are also several factors that contribute to this change in the organism, such as the use of medications and surgeries, for example. Know what these factors are:

Iron deficiency

Iron, as previously mentioned, is a fundamental nutrient for the health of the body. Among its functions, one of the most important is the role it plays in the formation of hemoglobins, a protein that represents approximately 30% of the weight of each red blood cell (red blood cells).

Without this nutrient, the bone marrow is unable to produce hemoglobins properly. With low levels of iron, our body ends up manifesting anemia.

In addition to a poor diet of this nutrient, the iron deficiency type can happen in pregnant women who do not receive supplementation, during their menstrual period and in patients with cancer, ulcers or in regular treatment with analgesics even if prescribed by the doctor, such as aspirin.

Diet low in vitamins

Vitamins B12 and B9, as well as iron, are essential for healthy red blood cells to be produced. Therefore, a diet deficient in these nutrients can cause anemia.

However, some people, even if they ingest a good amount of these vitamins, can develop anemia. This is because their bodies are unable to absorb them.

Various diseases can cause this malabsorption, which must be investigated and treated properly by the responsible physician.

Diseases associated with bone marrow

Diseases such as leukemia and myelofibrosis, which are related to changes in the function of the bone marrow, which is responsible for the production of blood cells (red blood cells, white blood cells and platelets. Therefore, they can cause anemia.

Intestinal disorders

Some diseases that affect the absorption of nutrients by the small intestine can increase the chances of anemia, such as intestinal malabsorption syndrome and Crohn’s disease.

Genetic or autoimmune diseases

Some genetic diseases, sometimes hereditary, can cause changes in hemoglobin, inhibiting the production or affecting the quality of these proteins .

The changes end up causing the erythrocytes to fail, in a shorter time than expected. The main pathologies that induce these dysfunctions are called hemoglobinopathies, such as those that cause sickle cell anemia and thalassemia (blood disorder due to low hemoglobin production).

In the case of autoimmune diseases, it is the individual’s own defense system that attacks red blood cells. Hemolytic anemia, for example, is a type of autoimmune anemia.

However, there are also autoimmune diseases that can present anemia as a symptom or consequence, such as celiac disease ( gluten intolerance ), which makes it difficult for the intestine to absorb nutrients.

Menstrual period

Women who have an intense or prolonged menstrual flow may be more likely to develop anemia, due to the blood loss that occurred during the period.

Generally speaking, women who are not in menopause are a higher risk group for anemia when compared to postmenopausal women and men.


Anemia during pregnancy is a symptom considered frequent, as during this period there is a decrease in the amount of hemoglobin. In addition, iron requirements increase and cannot always be met by food.

Risk factors

There are some factors that increase the risk of anemia. Are they:

  • Diet deficient in iron, minerals and vitamins such as B12 and B9;
  • Age: in the elderly, for example, the condition can occur due to the presence of chronic diseases, iron deficiency due to blood loss, inadequate nutrition and other inflammatory diseases;
  • Chronic diseases such as cancer, inflammatory bowel disease, liver disease, thyroid disease, diabetes, rheumatoid arthritis, AIDS, etc;
  • Blood loss triggered by surgery, injury, heavy menstrual flow or other causes;
  • Infections;
  • Pregnancy;
  • Medicines;
  • Family history, as in cases of sickle cell anemia;
  • Intestinal or gastric surgeries, such as bariatric surgery;
  • Intestinal disorders, such as Crohn’s disease.

Symptoms of anemia

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The symptoms of anemia can vary according to the type. In the case of iron deficiency anemia, for example, signs such as tiredness, apathy, indisposition, learning difficulties and pallor of the skin and mucous membranes, such as in the inner part of the eye and gums, may be present.

In general, anemia has the main symptom of tiredness due to less oxygen transport to cells and tissues. The faster anemia takes over the body, the more tiredness and weakness the patient feels.

The types of anemia that install slowly, in general, give the patient’s body time to adapt and symptoms may appear more intensely when there is a more severe stage.

Patients with acute anemia, for example, may have as a main characteristic a drop in blood pressure, due to the reduction in blood volume.

Under certain conditions, symptoms can be an impediment to performing simple everyday tasks. The main ones are:

  • Lack of energy;
  • Tiredness;
  • Loss of appetite;
  • Apathy (most noticeable in children, when they appear to be very “still”);
  • Cramps;
  • Learning difficulties (in children);
  • Chest pain;
  • Generalized fatigue;
  • Shortness of breathe;
  • Hypertension;
  • Indisposition to work;
  • Paleness of skin and mucous membranes (inner part of the eye, gums);
  • Tachycardia (racing heart).

However, as they are not specific signs, laboratory diagnosis is necessary. When identifying with the signs of anemia, it is essential to see a doctor to investigate the cause.


The diagnosis of anemia is always laboratory, through tests that allow the analysis of the amount of hemoglobin and red blood cells in the blood. From the values ​​indicated and the analysis of symptoms, the doctor will be able to analyze whether the case is anemia.

The hemoglobin level is one of the most used indicators to investigate the condition, information present in the blood count , routine examination commonly required for diagnosis of blood diseases.

This test points to the reference values ​​for erythrocytes, hematocrit and hemoglobin (blood cells), which are analyzed to identify whether the patient is producing healthy.

Reference values ​​may vary according to the laboratory and also according to the age and condition of the patient.

Women with large menstrual flow, for example, may have lower values ​​without causing any harm to their health. A slight drop in hematocrit, percentage of red blood cells or red blood cells in the total blood volume, in women may not be of clinical relevance.

During pregnancy, in order to prevent anemia in the baby, an investigation can be done on the mother during prenatal care. In the baby, anemia is confirmed by a blood test.

The general practitioner can examine the patient and make the diagnosis, but for treatment or for a differential diagnosis, other specialists can collaborate, such as the pediatrician, hematologist and nutritionist.


The diagnosis of anemia is confirmed by performing some tests, such as a blood count, commonly used in the suspicion of anemia.

The blood count is a blood test that specifies information such as hemoglobin levels, which may not be altered during the onset of the condition, but which tends to show variation over time.

Generally, at the onset of anemia, red blood cells are of normal size and color, but they become smaller (microcytic) and pale (hypochromic) with the aggravated condition.

Among the information that the blood count test presents are the average amount of hemoglobin per red blood cell and the volume, which may be lower in anemia. It is also possible to identify whether there is variation in the size of red blood cells, which may be larger.

When there is a suspicion that this is a case of iron deficiency anemia, the doctor may request further tests.

In addition to the blood count, those that can be ordered include:

  • Ferritin : performed to measure the amount of ferritin in the blood, a protein responsible for storing iron in cells. Low amounts of ferritin in the blood consequently represent a reduction in the amount of iron stored by the body;
  • Serum iron : is a test to determine the level of iron in the blood, requested when there is a suspicion of excess or deficiency of iron in the body. It is carried out through a blood sample, being necessary to fast for, on average, 12 hours until blood collection;
  • Transferrin: used to evaluate the blood’s capacity to carry out iron transport, transferrin being the protein that binds to iron in the blood for this transport in the body to happen;
  • ESR (erythrocyte sedimentation rate) : it is performed to identify inflammations. In the case of anemia, it helps in the diagnosis when the cause is an autoimmune disease.

Reference values ​​for the complete blood count

The blood count reference values ​​vary according to sex and age. Considering the hemoglobin values (g / dL) in the blood, the following indices are established:

  • Newborns: 13.5 to 19.6;
  • Children up to 1 year of age: 11 to 13;
  • Children over the age of 1 year: 11.5 to 14.8;
  • Women: 12 to 16;
  • Pregnant women: 11.5 to 16;
  • Men: 13.5 to 18.

The diagnosis of anemia is made when these hemoglobin values ​​are below the reference value. To identify the cause, other tests, prescribed by the doctor, may be necessary.

And it is important to note that the doctor responsible for the request must interpret the test result . Changes in results are not always anemia.

Can anemia be cured?

The cure for anemia depends on the cause. Normally, anemia caused by iron or vitamin deficiency can be treated and resolved more easily.

In anemias caused by autoimmune or genetic diseases, for example, a cure is not always possible. However, there is the possibility of treatment and control of the condition.


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The treatment is carried out according to the cause of the anemia, and can be done through nutritional support, with replacement of iron and vitamins, for example, or with the treatment of the diseases that cause this symptom.

In some cases, just a more adequate diet is not enough to cure anemia, requiring the use of specific supplements or medications.

See how the treatment should be, according to the cause:

Vitamin B12 deficiency anemia

For treatment, what must be investigating is causing this lack of vitamins.

When it comes to a deficiency due to inadequate nutrition, a change in diet can be made. The doctor can guide the patient in this regard, with the nutritionist being an important professional for follow-up.

In the case of a deficiency caused by malabsorption, it is important to seek treatment for the disease that is preventing the use of these nutrients.

It may be necessary to replace these vitamins with supplements. Who should analyze this need is always the doctor responsible for the case.

Iron deficiency anemia

Treatment is usually given by the use of medications or supplements prescribed by the doctor. In addition, a nutritional change is also important, so that the body can absorb iron through foods of animal and vegetable origin. Some of the best sources of this nutrient are:

  • Red meat : mainly liver, from any animal, and other offal (small), such as kidney and heart;
  • Poultry and fish meats;
  • Foods of vegetable origin : dark green leaves such as watercress, kale, green scent, beet leaves;
  • Legumes : beans, beans, chickpeas, peas, lentils;
  • Whole or enriched grains : nuts and chestnuts, cane molasses, brown sugar, brown sugar.

There are also foods enriched with iron available on the market, such as wheat flour, corn flour and breakfast cereals, for example.

However, if the cause of iron deficiency anemia is not food, but bleeding, in addition to nutritional replacement, it is necessary to investigate and treat what is causing this excessive blood loss.

In the case of women who have a prolonged menstrual flow, it is worth consulting with a gynecologist to understand what can be done to prevent anemia.

Other types of anemia

When anemia is caused by autoimmune or genetic diseases, treatment must be carried out to treat these specific diseases. Thus, the cure for anemia happens indirectly.

Depending on the type of anemia, it may be necessary to administer medications to inhibit the immune system (hemolytic anemia), medicines to relieve pain and blood transfusions, in more severe cases.

In the case of sickle cell anemia, for example, bone marrow transplantation may be necessary.


The use of medications should be done when prescribed by the doctor responsible for the treatment, according to the needs of the patient.

In the treatment of iron deficiency anemia, the most common type, the use of drugs based on ferrous sulfate may be prescribed.

In megaloblastic anemias, medication with the active substance calcium folinate can be recommended. Other drugs used to treat anemia include:

  • Dexamethasone ;
  • Folic Combiron ;
  • Ferronil ;
  • Hemax ;
  • Hemogenin ;
  • Neutrofer ;
  • Noripurum ;
  • Noripurum Folic ;
  • Prednisolone .


NEVER self-medicate or stop using a medication without first consulting a doctor. Only he will be able to tell which medication, dosage and duration of treatment is the most suitable for his specific case. The information contained on this site is only intended to inform, not in any way intended to replace the guidance of a specialist or serve as a recommendation for any type of treatment. Always follow the instructions on the package insert and, if symptoms persist, seek medical or pharmaceutical advice.


Anemia is a symptom, so to make an adequate prognosis, it is necessary to understand the cause. Usually, patients who follow the treatment and medical guidelines to the letter have a positive and uncomplicated prognosis.


When anemia is not treated, some complications can occur. In the case of the sickle cell type, for example, the absence of a treatment can be serious, causing complications even lethal.

Some of the most common are apathy, low birth weight in newborns, reduced productivity at work, reduced learning capacity (especially in children), stunted growth and reduced cognitive ability that can be permanent.

Other complications that anemia can cause:

Heart problems

Anemia can cause changes in the heartbeat rhythm, making it fast or irregular (arrhythmia). Under these conditions, the heart tries to compensate for the lack of oxygen and nutrients in the tissues by increasing the pumping of blood. Therefore, the organ is more required.

Severe fatigue

Anemia, in severe cases, causes a feeling of extreme tiredness in the patient. This fatigue can prevent you from performing tasks easily, having difficulty working, studying and other day-to-day activities.

It is a risk for pregnant women and the baby

Due to aggravated anemia, pregnant women may have a premature birth . In addition, this symptom is considered the primary cause of between 1 and 5 deaths in women in labor.

How to prevent?

Not all types of anemia can be prevented, as in the case of anemia caused by autoimmune and genetic changes. But, when we refer to iron deficiency anemia or vitamin B12 deficiency, there are some tips and healthy habits that can help:

Include iron-rich foods in your diet

A diet rich in iron helps prevent iron deficiency anemia, as this is a fundamental nutrient for the healthy production of red blood cells (red blood cells).

Therefore, it is important to include foods such as quinoa , beans , poultry, fish, beef, lentils, chickpeas, and leafy vegetables such as kale, spinach and watercress.

Consume foods with vitamin B9 (folic acid) and B12

Folic acid (vitamin B9) and vitamin B12, as well as iron, are also essential for preventing anemia.

Vitamin B9 is present in dark green leafy vegetables, in peas, beans, grains, peanuts, bread, cereals and rice. Vitamin B12 can be acquired in diets rich in dairy products, cereals, soy products and meats.

Moderate consumption of calcium-rich foods

Calcium is also an essential nutrient for health, but it can interfere with the body’s absorption of iron.

However, studies on this effect are still not very consistent to say how much it interferes with the absorption of iron by the body and how much would be a risk.

To prevent anemia, calcium intake should not be excluded, but it is recommended that the intake of foods that are sources of iron at the same time as the consumption of foods rich in calcium should be done according to the recommendation prescribed by a doctor or nutritionist, as they are the most suitable professionals to evaluate each case, individually.

Vitamin C

The presence of vitamin C (ascorbic acid) in the meal improves the absorption of iron from plant products, such as broccoli, beets, cauliflower and others.

Some good sources of this nutrient are fruits like lemon, orange, cashew, acerola, pineapple, strawberry, guava, papaya, cranberry and mango .