Anemia: what it is, types, causes, symptoms, treatment and prevention

Anemia: what it is, types, causes, symptoms, treatment and prevention

Anemia is a condition in which the number of red blood cells and the concentration of hemoglobin in the blood are insufficient to carry enough oxygen to meet the needs of all body tissues. According to the World Health Organization (WHO), the hemoglobin levels below which we can speak of anemia are 13.4 g/dL for men and 12 g/dL for women.

It is not a disease itself, but a symptom of an underlying disease. Therefore, depending on the cause that generated it, there are different forms of anemia, each with different levels of severity.

However, the decrease in hemoglobin concentration can be temporary, event-related (such as surgery or trauma), or chronic.

In fact, the lack of vitamins (especially vitamin B12, vitamin C or folic acid), minerals (such as iron), some intestinal disorders (including celiac disease) and conditions such as heavy menstrual flows or chronic diseases expose you to a greater risk of anemia. Also, it is easier to get iron deficiency anemia during pregnancy.

Although it may initially be asymptomatic, the symptoms of anemia are rather general such as tiredness, paleness, tachycardia, increased respiratory rate, dizziness and headache.

Anemia can be diagnosed through a blood test. Treatment, on the other hand, varies depending on the underlying causes.

What is anemia

Anemia is a condition in which the number of red blood cells and the hematocrit and hemoglobin levels in the blood are not sufficient to ensure oxygenation of peripheral tissues.

According to the diagnostic criteria currently in use, in men anemia is considered the condition in which red blood cells are less than 4.5 million/μl (for women 4 million/μl), the hematocrit is below 42% ( 37% in women) and the hemoglobin is less than 13.4 g/dL (12 g/dL for women).

Hematocrit is the percentage of the unit volume of blood occupied by red blood cells.

But before considering anemia and its possible treatments, it is necessary to identify the cause that generated it. In fact, in the absence of specific information on the etiological aspects of the disorder, it is only possible to temporarily restore a balance in the oxygenation capacity of the tissues.

Symptoms of anemia

What symptoms can anemia give? Initially it may be asymptomatic, but with the passage of time and the persistence of the condition of poor oxygenation of the cells, nuanced and not very specific symptoms appear such as:

  • Tiredness: the scarce availability of oxygen removes nourishment from the cells, which thus encounter difficulties in carrying out the common metabolic reactions.
  • Pallor: poor oxygenation of the skin and subcutaneous tissue determines the pallor of the skin and mucous membranes, including the conjunctival; especially the latter sign has been used as a diagnostic criterion in the past.
  • Alteration of the heart rhythm: to supply the same quantity of oxygen to the tissues in conditions of reduced concentration, an increase in the number of heartbeats per unit of time is required (tachycardia); the pulse is weak and rapid.
  • Increased respiratory rate: the body enters into conditions of respiratory distress (tachypnea) in an attempt to compensate for the poor oxygenation of the blood; in severe forms of anemia the patient may have real breathing difficulties (dyspnoea).
  • Dizziness, fainting and cognitive disturbances: these symptoms are caused by reduced oxygenation of the brain; Cognitive disorders occur more frequently in elderly subjects than in the young population and are sometimes confused with dementia.
  • Cold extremities.
  • Pronounced sweating.
  • Leg cramps: appear in cases of severe anemia.
  • Headache.

In addition, there are symptoms that may be indicative of the cause of anemia, such as:

  • Presence of blood in the urine or stools (which may be a sign of bleeding in the kidney, urinary tract or gastrointestinal tract).
  • Jaundice (condition in which the skin and mucous membranes turn yellow, indicative of an increase in the destruction of red blood cells).
  • Paresthesias (tingling may be a sign of vitamin B12 deficiency).

Types of anemia

There are different forms of anemia, each caused by different factors. These types also differ in the characteristics of chronicity more or less present and in the characteristics of the disease.

Mediterranean anemia

Mediterranean anemia or thalassemia is caused by a mutation of the genes that encode the production of one of the two proteins that make up hemoglobin, the means of transporting oxygen in the blood.

It is therefore a widespread hereditary pathology especially in the areas bordering the Mediterranean basin. In America, the highest incidence is found in Sardinia.

Mediterranean anemia is a form of microcytic anemia, in which red blood cells fail to develop to reach their physiological size.

If you want to know more, read our study on Mediterranean anemia.

sickle cell anemia

Sickle cell anemia or sickle cell disease is a genetic disease of the blood, therefore hereditary, more precisely, of hemoglobin (the protein that carries oxygen and is present in red blood cells).

It is characterized by the presence of sickle-shaped red blood cells (or erythrocytes) and chronic anemia.

In fact, in healthy subjects, red blood cells have a rounded shape and a smooth surface which make them suitable for passing through capillaries, even the thinnest ones, to carry oxygen to the tissues and organs of our body. In contrast, in sickle cell anemia, red blood cells are stiff, have an irregular surface and are crescent-shaped. Due to these characteristics, they can therefore obstruct the smallest vessels and not carry enough oxygen, causing pain and damaging organs and tissues. They then have an average life of 10-20 days against the 120 of normal erythrocytes.

If you want to know more, read our study on sickle cell anemia.

Vitamin deficiency anemia

Vitamin deficiency anemia is decreased production of red blood cells caused by a vitamin deficiency. The vitamins involved are vitamin B12, folic acid (vitamin B9) and vitamin C (ascorbic acid).

Mature red blood cells are larger than normal (this is a megaloblastic anemia) and few in number, because most are destroyed soon after production in the blood marrow.

Folic acid deficiency anemia is generally associated with a diet deficient in this vitamin. Pregnant or breastfeeding women have an increased demand for folic acid, which must be supplied via dietary supplements. Folate deficiency during pregnancy can affect the development and growth of the fetus and cause neural tube malformations (spina bifida).

Even chronic intestinal diseases (such as ulcerative colitis and Crohn’s disease) and celiac disease, pathologies involving alterations in the absorption capacity of the intestinal villi, may be at the basis of this form of anemia, as well as intestinal bypass.

Anemia sideropenica

Iron deficiency anemia (also called iron deficiency anemia) is due to iron deficiency and is the most common type of anemia. It is usually secondary to blood loss, either covert and chronic (as in the case of a tumor or ulcer) or acute, due to trauma or surgery.

But other causes can be represented by a low intake with nutrition (frequently occurs together with very drastic diets or associated with eating disorders) and problems in the absorption of iron (for intestinal diseases or intestinal bypass surgery).

The lack of adequate levels of iron penalizes the transport of oxygen in the blood causing tiredness, increased respiratory rate and pallor.

However, it is a form of microcytic anemia, in which the erythrocytes are unable to develop to reach their physiological size.

Hemolytic anemia

Hemolytic anemia includes a group of diseases characterized by an alteration in the function of the immune system, with the production of antibodies directed against red blood cells, which are attacked and destroyed by mistake.

This form of anemia can appear at any age and is more common in the female population.

If the disease occurs in a mild form, the affected person may also be asymptomatic. People with the intermediate form experience symptoms such as tiredness, shortness of breath, and pale skin. In addition, the severe form includes jaundice (due to the accumulation of the hemoglobin metabolite, bilirubin, in the skin and mucous membranes) and abdominal swelling, caused by splenomegaly (the spleen becomes hypertrophied due to the increased activity of elimination of erythrocytes).

If you want to know more, read our in-depth study on haemolytic anemia.

Anemia aplastica

Medullary dysplasia is a condition in which the bone marrow tissue responsible for the production of blood cells (hematopoietic red marrow) is damaged (hypoplasia) or destroyed (aplasia) and which results in a reduction in the production of red blood cells, but also of white blood cells and platelets. More often than not, it is the continuous and prolonged destruction of blood cells that subjects the hematopoietic marrow to extraordinary stress, aimed at their replacement. This effort, extended over time,…