The average lifespan of the red blood cells is about 120 days. Every hour is nine billion worn-out red blood cells taken out of circulation and broken down. The organism usually forms the same number of new blood cells in bone marrow, where most of the production of blood cells takes place. A distinction is made between several main causes of anemia:
1. Bleeding Anemia
In a major bleeding occurs an acute shortage of blood. Blood loss must be replaced immediately, otherwise the patient into a life-threatening shock, supported by high blood pressure. The acute and major bleeding condition must immediately be treated with fluids, preferably directly into the bloodstream (blood transfusion). The organism can pretty quickly replace the plasma with tissue fluid that seeps into the blood vessels and may also quickly remedy the loss of white blood cells and plasma proteins. The organism can not increase its production of hemoglobin and red blood cells rapidly. In a liter of blood is the same number of red blood cells that the organism normally produces in a month. Therefore, the recovery time after a severe bleeding anemia demonstrated that slowly improves.
It is characteristic that in this phase can be detected increased numbers of immature red blood cells (reticulocytes). A similar but chronic bleeding-related anemia may be caused by seeping bleeding from internal organs (such as bleeding ulcers), strong, long lasting menstrual bleeding or hemorrhoids.
2. Anemia with impaired production of red blood cells.
Radiation injuries may be the cause of the anemia of this type and also to a number of disorders of the bone marrow, where the production of normal blood cells is reduced or stopped (leukemias and aplastic anemias).
3. Mangelanemier
This is the most common anemia. When a deficiency anemia is the organism loss of another material that is necessary for the production of blood cells. Hit hearing including iron deficiency anemia and megaloblastanemi.
4. Hemolytic anemias
Hemolytic anemia due to red blood cells are destroyed so fast that production is not keeping pace with consumption. Enhanced hemolysis (breakdown of blood cells) seen in hereditary structural defects in red blood cells, after insertion of artificial heart valves, as adverse reactions to the use of certain drugs and in autoimmune conditions. In almost one third of the cases detected no certain explanation. Some important types of anemia does not fit into this classification. On a number of chronic conditions (infections, inflammation, and cancer immunopatier) demonstrated mild to moderate anemia (Hb 12.9 g/100 ml), where the individual red cells can have a normal size and content of hemoglobin. The cause is often multifactorial (lack of iron and vitamin B 12 in particular due. Malabsorption, possibly complicated with increased hemolysis, decreased release of iron from the store, or reduced production of normal red blood cells due. Due to illness, etc.). There are also hereditary conditional errors in the production of hemoglobin.
5. Hereditary anemias contingent
There are forms of inherited anemia, "retreating" (recessive) and resulting from genetic errors in the blood pigment hemoglobin. One category of such anemias (thalassemia) are particularly frequent in Mediterranean countries, another (sickle cell anemia) in Africa.
In thalassemia, the production of hemoglobin defect, and by the severe form (thalassemia major), the patient must regularly receive blood transfusions or undergo a stem cell transplant . New technology has made it possible to determine whether the fetus has genes for thalassemia and other inherited defects in hemoglobin synthesis. Both parents of children with thalassemia in the severe form are carriers of a genetic defect of hemoglobin, but this is balanced by the fact that these people also have a normal gene for the production of hemoglobin. They feel very rarely sick even if they have moderate anemia (thalassemia minor). Average one-quarter of children to two facilities will be disease carriers unit from each parent.