Anemia: Causes, Symptoms, Complications, Diagnosis, Treatment and Prevention

It is a disorder characterized by an abnormally low number of healthy red blood cells in the blood.

This blood disorder is characterized by a deficiency of red blood cells or hemoglobin (the protein-forming cells) in the blood.

The bone marrow makes red blood cells.

The deficiencies result from the lack of production of red blood cells or even their destruction.

Red blood cells carry oxygen throughout the body, so an insufficient number of red blood cells can have serious consequences.

Causes of anemia

Anemia is not a disease but a condition attributable to other health conditions.

A combination of factors can cause anemia. Anemia is widespread in people with cancer.


About half of people with cancer develop anemia.

Causes can be multiple and include bone marrow tumors, blood loss, dietary deficiencies, chemotherapy, radiation that destroy the bone marrow, where red blood cells are produced, or a combination of these factors.

In people with severe kidney disease, anemia is caused by decreased red blood cell production, shortened red blood cell lifespan, and blood loss associated with dialysis treatment.

Various forms of anemia are defined as:

central anemia

They are directly related to low hemoglobin and red blood cell production. Five main risk factors cause them:

Lack of iron

Iron is one of the main components of hemoglobin.

Its mission is to promote oxygen fixation in this cell to transport it into the body.

The body needs iron to make hemoglobin; this protein in red blood cells carries oxygen from the lungs to the rest of the body.

Hemoglobin also gives blood its red color.

The lack of iron causes a decrease in oxygen in hemoglobin, and in the long run, this causes a reduction in their size and number.

Iron deficiency anemia is the most common type of anemia.

It is widespread among children and women of all ages, especially women who are still menstruating.

It is estimated that at least one-fifth of women suffer from iron deficiency.

It can also significantly affect men when caused by colon polyps, cancers, or other gastrointestinal malignancies.

Iron deficiency anemia is often one of the first warning signs of gastrointestinal cancer.

Vitamin deficiency

Vitamins B9 and B12 are folic acids that play a vital role in maintaining and producing red blood cells.

People who need more iron intake include babies, pregnant women, and growth-slamming teens.

They are essential for manufacturing porphyrins, molecules involved in oxygen transport.

Pernicious anemia is a more common form of anemia in the elderly and is caused by a dietary deficiency of vitamin B12 or poor absorption of this vitamin from the intestines.

This condition is also frequently found in alcoholics.

Renal disease

Anemia is common in people with severe kidney problems because the kidneys secrete erythropoietin hormone.

Erythropoietin is a hormone produced by the kidneys.

It is essential for the production of red blood cells, as it has the role of stimulating the bone marrow when the body needs them.

The amount and effectiveness of erythropoietin are reduced when the kidneys are affected by pathologies.

In kidney problems, the kidneys cannot make enough of this hormone for the body to receive red blood cells properly, leading to anemia.

An inflammatory disease

Certain diseases will be at the origin of the manufacture of inhibitory substances. They impede the red blood cell production process.

Inflammatory anemia is a mild form of anemia that affects people with illnesses lasting longer than 1 to 2 months.

The diseases involved include tuberculosis, HIV, cancer, kidney and liver, and rheumatological disorders.

Dysfunction of the bone marrow

It is related to a decrease in the production of red blood cells.

The lifespan of a red blood cell is only four months, and the red blood cells need to be replaced by new ones produced in the bone marrow.

If you have aplastic anemia, the bone marrow is destroyed, or if there is a severe injury, it can no longer make red blood cells.

Some medications and radiation can destroy the bone marrow, but the most common cause is an autoimmune reaction.

Such a reaction occurs when the cells that protect the body against disease attack the person’s tissues.

In 50% of cases, the cause of the autoimmune reaction is unknown.

Other diseases can destroy the bone marrow and cause aplastic anemia, including viral hepatitis and severe rheumatoid arthritis.

Fanconi disease is a rare inherited aplasia characterized by abnormalities in the bone marrow.

It can come from natural or premature aging of the tissues that compose it and produce red blood cells.

This aging can be caused by severe diseases such as cancer or a disease caused by toxic products called aplastic anemia.

Aplastic anemia is a rare disorder when the bone marrow no longer produces blood cells.

This type of anemia is severe, but fortunately, it is also rare.

The incidence of this disorder is 2 to 12 new cases per million people per year.

Adults and children can be affected by this form of anemia.

Sickle cell anemia (sickle-shaped red blood cells)

It is another known form of anemia.

Millions of people around the world suffer from it.

It is a hereditary condition passed from parent to child through faulty genes.

The most frequently affected people have ancestors from Africa, the Middle East, Mediterranean countries, or India.

One in every 400 births will produce a newborn with sickle cell disease in the African American population.

Sickle cell anemia is widespread among people of African American descent, while thalassemia is more common in families of Mediterranean origin.

Sickle cell anemia and thalassemia are two inherited disorders characterized by an abnormal shape of red blood cells.

Sickle cell anemia occurs in a person who receives a copy of the gene for sickle cell disease from their father and mother, which results in the production of red blood cells that are abnormally shaped.

The spleen recognizes these red blood cells as abnormal and must work harder and harder to remove these blood cells, causing an increase in the volume of this organ.

Peripheral anemias

They are rare and are due to a loss or destruction of red blood cells that two critical phenomena can explain:

Significant blood loss

Red blood cells are flushed out of the body during heavy bleeding.

We are talking about hemorrhagic anemia.

Menstruation and bleeding are often the cause of these losses.

Many women have anemia, in general, because their diets do not provide enough nutrients to replace monthly menstrual bleeding.

Gastrointestinal bleeding is another common cause of blood loss; These bleeds can be caused by ulcerative colitis, diverticulitis, and colon cancer.

Certain medications such as acetylsalicylic acid and non-steroidal anti-inflammatory drugs can also cause gastrointestinal bleeding.

The following conditions can also cause bleeding:

  • Gastric ulcers
  • Hemophilia.
  • Hemorrhoids.
  • Ancylostoma.

Poor persistent bleeding can also lead to anemia.

Even a healthy person can lose a small amount of blood every day in their stool.

Slightly more blood loss can go unnoticed and cause anemia.


This is a pathology characterized by the abnormal destruction of red blood cells.

This is called hemolytic anemia. The disease can be genetic or autoimmune (the immune system fights its cells).

The bone marrow makes a specific number of red blood cells each month.

If the destruction of red blood cells is faster than the production rate, anemia sets in.

The old red blood cells are mostly broken down by the spleen, the organ in charge of filtering the blood.

This organ checks that the blood is not infected and removes harmful substances.

Some conditions cause an increase in the volume of the spleen.

For example, liver disease or lupus are two possible causes of hypersplenism (enlarged spleen); malaria and tuberculosis.

When the spleen is more significant than usual, it retains and destroys healthy red blood cells, causing anemia.

Symptoms and complications

Anemia is characterized by paleness, tiredness, headaches, palpitations, shortness of breath, or problems with balance.

The symptoms are more or less variable and visible depending on the origin of the disease.

Symptoms of anemia vary according to the importance of decreasing the number of red blood cells.

Menstrual bleeding or iron deficiency tends to cause mild chronic anemia, the symptoms of which are fatigue, paleness, and weakness.

If the anemia is caused by severe bleeding, such as a severe ulcer gastrointestinal bleed, you may feel dizzy and very weak, especially if you stand up suddenly.

In severe anemia, tissues and organs can be deprived entirely of blood and oxygen.

If so, cells quickly die during a process called ischemia.

The red blood cells, usually round in shape, look like a sickle in sickle cell anemia.

Due to this abnormal shape, cells remain blocked in the small blood vessels and hinder the normal flow of blood.

People with this condition can suffer severe ischemia in the feet, sometimes leading to amputation, or other organs, causing pain.

People with this form of anemia are at high risk for stroke because sickle cells can easily clump together and form a clot that blocks blood flow to the vessels in the brain.

In people with cancer, the most common symptoms of anemia are fatigue and shortness of breath.

It can be difficult for these people to continue their activities and maintain their usual energy level, which can have very adverse effects on activities of daily living.

Diagnosis of anemia

It is necessary to establish a diagnosis.

The doctor will usually take a blood sample and prescribe a blood count in the laboratory.

This whole blood test is based on three measurements.

Calculation of hemoglobin

There are rates below which anemia can be reported.

There is talk of anemia when hemoglobin falls below specific values ​​, such as:

  • 130 g / l for an adult man.
  • 120 g / l for an adult woman.
  • 110 g / l for a pregnant woman.
  • One hundred forty grams per liter of blood (g / l) for a newborn, 115 g / l for a child from 5 to 11 years old, and 120 g / l for a child from 12 to 14 years old.

In children, this rate changes with each stage of growth.

Calculating the hematocrit rate

This is the place occupied by blood cells in the blood.

It allows to know the size of the red blood cells and thus specify the origin of the disease.

Calculating the reticulocyte rate

This is the number of new red blood cells produced by the bone marrow.

When the number of red blood cells is more significant than 150,000 (per milliliter of blood), the body can regenerate enough cells.

This is known as regenerative anemia, often characteristic of peripheral anemias.

The number of red blood cells produced is sufficient, but the losses are too significant to prevent anemia.

The result then expresses the number of grams of hemoglobin per liter of blood, the number of white blood cells, platelets, and other blood elements.

The size and shape of the red blood cells will also be examined.

These tests tell the doctor about the number of different blood cells and their shape, which provides clues to the cause of anemia.

For example, the number of white blood cells and red blood cells below average can be a sign of damage to the bone marrow or spleen.

The doctor then looks for other diseases based on the first blood test results.

Treatment and prevention of anemia

The underlying disease-causing this anemia determines the treatment choice for anemia.

Severe bleeding is usually treated with blood transfusions.

If you have a severe form of chronic anemia, such as Fanconi disease or sickle cell anemia, you may need regular blood transfusions.

The life expectancy of people with sickle cell anemia has improved a lot. In the old days, the young often did not reach adulthood.

Iron supplements are given to treat iron-deficiency anemia.

Babies with this form of anemia often receive unique formulas in their milk bottles.

The baby’s body can absorb more iron in breast milk than cow’s milk.

Nursing mothers can take iron supplements.

The latter is also helpful in treating mild anemia caused by gastrointestinal bleeding or menstrual bleeding.

Vitamin B12, vitamin C, and folic acid play a crucial role in producing red blood cells.

The deficiency of any of these vitamins carries a risk of anemia.

Beef and fish are good sources of vitamin B12.

Vegetables do not contain this vitamin; a person who does not eat meat, fish, or dairy products needs to take a vitamin B12 supplement.

Folic acid is present in spinach, peas, oranges, and melons.

When anemia is caused by reduced red blood cell production, such as cancer or severe kidney disease, drugs called epoetin alfa and darbepoetin alfa may be used.

These drugs mimic the action of the natural hormone erythropoietin resulting in increased production of red blood cells by the bone marrow.

Anemia during pregnancy

Anemia can result from a deficiency of vitamin B9, also known as folate or folic acid.

This risk is more significant in pregnant women since their folic acid needs increase by 30% to satisfy the proper development of the embryo’s nervous system.

Therefore, it is recommended that women who want to have a child or a pregnancy receive vitamin B9 supplements.

Iron, the lack of which also leads to anemia, should also be monitored.

On the contrary, only the doctor can evaluate the need to prescribe pharmacological supplements for this trace element because an overdose can be harmful.

If anemia is diagnosed and treated quickly, there are no consequences.

On the other hand, if it is not diagnosed in time, it can aggravate the situation of a cardiac patient or that of a patient suffering from respiratory failure.