Synonyms
Anemia, blood deficiency, bleach-seeking English: anemia
Definition
Anemia is a common symptom. Anemia is a reduction in the number of red blood cells (erythrocytes), the red blood pigment (haemoglobin) and/or the cellular component of the blood (haematocrit). The haematocrit describes the percentage of blood cells in the total blood volume.
The erythrocytes are formed in the bone marrow and have a lifespan of about 120 days. Their diameter is about 7.5 μm. They are round, dented on both sides and deformable. The blood formation of red blood cells (erythropoiesis) takes about 5 – 7 days. The breakdown takes place regularly in the spleen.
Classification of anaemia
The classification of the anemia is made according to:
- The volume of red blood cells: macrocytic, normocytic, microcytic
- The haemoglobin content (protein that transports oxygen and contains iron): hypochrome, normochrome, hyperchrome
- The cause: blood loss, synthesis disorder, increased breakdown (haemolysis)
- The bone marrow findings
Forms of anaemia
Anemia can be divided into different forms: In the respective topic you will learn more about the diagnosis, cause and specific therapy. – Iron deficiency anaemia
- Megaloblastic anemia
- Pernicious anemia
- Haemolytic anaemia
- Aplastic anemia
General introduction and causes
Anaemia is a reduction in haemoglobin. This is an oxygen-carrying protein in the body. It is found throughout the body in the red blood cells (erythrocytes) and thus serves to supply the organs with oxygen.
A decrease in haemoglobin can have both congenital and acquired causes. Due to anaemia, the body reacts with an increased heart rate and a reduced ability to cope with stress. This leads to various symptoms.
Depending on the cause of the anemia, there are various therapeutic options. Depending on the above-mentioned blood values, anaemia is divided into different forms. This is also a classification of the cause of the different forms of anaemia.
Normochrome, normocytic anaemia describes anaemia with normal red blood cells and a normal haemoglobin content (red blood pigment). The total number of red blood cells is reduced. The cause of such anemia is often an insufficient effect of the hormone erythropoietin or cytokine.
Erythropoietin is produced in the kidney and stimulates the production of red blood cells in the bone marrow. The reason for an erythropoietin deficiency can be kidney disease or a low metabolic state. For example, as a result of an underactive thyroid (hypothyroidism), pituitary insufficiency (hypopituitarism) or a protein deficiency.
Similarly, aplastic anaemia can lead to normochromic, normocytic anaemia. The erythropoietin content is usually normal. In contrast, the precursor cells in the bone marrow are reduced, so that not enough red blood cells can be produced.
The exact cause is unclear; a genetic form is described, which is called Fanconi anaemia. It can also have an influence on the formation in the bone marrow. However, this damage is unspecific and also affects the other precursor cells in the bone marrow.
The haematopoietic bone marrow can also be damaged by certain:. However, this then leads not only to a disturbance of the red blood cells, but also of the other blood cell lines. Hyperchromic macrocytic anaemia describes a form of anaemia with particularly large red blood cells rich in haemoglobin.
However, the number of red blood cells is reduced. The reasons for this are:
- Radiation
- Chemicals
- Infections
- Medicines or
- Chemotherapy
- Malignancies (malignant tumours)
- Metastases
- Malignant lymphomas (lymph gland cancer) or
- Leukemias
- A lack of vitamin B12
- Thiamine or
- Folic acid. Vitamin B12 is needed in the body for DNA synthesis (genetic material).
Since there is not enough DNA available for synthesis in case of a deficiency, the red blood cells become too large in comparison. A vitamin B12 deficiency can result from insufficient intake with food or malabsorption (uptake disorder). In order for vitamin B12 to be absorbed in the intestine, the intestinal mucosa needs the intrinsic factor (IF).
If this factor is missing or not available in sufficient quantities, vitamin B12 cannot be absorbed. This can have acquired or congenital causes. Likewise, chronic inflammatory bowel diseases, tapeworm infestation or other intestinal diseases can lead to a deficiency of vitamin B12.
During pregnancy, childhood and malignant tumour diseases there is an increased need for vitamin B12. If this is not covered by sufficient intake, anaemia also develops. Folic acid serves as a coenzyme in the synthesis of purines, thymine and methionine.
A deficiency also leads to a disturbance of the DNA synthesis. The causes largely correspond to those of a vitamin B12 deficiency. Insufficient intake, intestinal diseases or an increased requirement during pregnancy and childhood without a corresponding additional intake cause a deficiency.
The third form is hypochromic, microcytic anaemia. Here the red blood cells are too small and contain too little haemoglobin. This form of anaemia usually occurs as a result of iron deficiency.
With about 80% it is the most common form of anaemia. This is called iron deficiency anaemia. An increased iron loss due to bleeding, for example in the digestive tract, is often the cause of an iron deficiency.
The iron content in the body can also be too low due to poor absorption in the case of diarrhoea or gastric acid deficiency. Iron deficiency anaemia can also be caused by defects in the transport proteins of iron (transferrin) or by kidney disease and the resulting high iron loss. Insufficient iron utilization occurs, for example, in thalassemia or sickle cell anemia and also leads to anemia.
The following can also trigger iron deficiency anaemia and thus anaemia. You can find out more about this anaemia in our topic: Iron deficiency anaemia. – Cancer diseases
- Autoimmune diseases and
- Acute or chronic infections
