Why does blood hemoglobin decrease: causes, symptoms and treatments

2024 Author: Curtis Blomfield | [email protected]. Last modified: 2024-01-02 05:35

Why does hemoglobin in the blood decrease? Dizziness and skin and hair problems are just some of the symptoms.

Hemoglobin is the main component of red blood cells and ensures the transport of oxygen from the lungs to all tissues of the body, as well as the transport of carbon dioxide in the opposite direction. Human blood contains approximately 750 g of hemoglobin. With its deficiency, all cells of the body receive less oxygen. This element provides the process of cell respiration, that is, the production of energy necessary for life. With oxygen deficiency, the functioning of all cells, tissues and organs is disrupted. Nervous tissue is especially sensitive to oxygen starvation. That is why hemoglobin in the blood decreases, and dizziness and fatigue bother patients.

Erythrocytes are formed in the red bone marrow, where hemoglobin begins to accumulate. Its molecule contains iron atoms, and some vitamins are needed for the formation of red blood cells. Iron deficiency results in small amountshemoglobin, and with a lack of vitamins (cyanocobalamin (B_{12) and folic acid), the normal formation of red blood cells is disrupted. Iron deficiency is the most common cause of low hemoglobin. It can be caused by insufficient food intake. But there are other reasons as well. In some conditions, iron deficiency occurs even with sufficient intake from food. This element, like all other substances, is absorbed from food in the small intestine. Diseases of this department will lead to a decrease in the flow of all substances into the blood, including iron. Next, all situations will be considered in more detail, why hemoglobin in the body may decrease.}

Classification of anemia

The condition of the body caused by insufficient hemoglobin in the blood is called anemia. Based on WHO recommendations, the following criteria for anemia have been adopted:

for women, hemoglobin level ≦ 120 g/l (for pregnant women - less than 110 g/l);
for men Hb ≦ 130 g/l;
for children Hb ≦ 110 g/l.

In Russia and the CIS countries, anemia is classified according to the hemoglobin content in one erythrocyte (by color index):

hypochromic (CPU < 0, 8);
normochromic (CPU 0.8 - 1.05);
hyperchromic (CPU > 1, 05).

The distribution of this classification is easily explained. You can determine the CPU in a regular clinic using a portable hemoglobin analyzer for a minute, and capillary blood (fromfinger).

In other countries (and more recently in our country), a classification based on measuring the volume (size) of red blood cells (MCV) is also used. Both classifications of anemia overlap and can be combined:

microcytic (MCV < 80 fl) hypochromic;
normocytic (MCV 80-100 fl) normochromic;
macrocytic (MCV > 100 fl) hyperchromic.

MCV is now included in the regular CBC list and can be measured in any lab with an automated analyzer.

Microcytic hypochromic anemias

This group of anemias is determined by a number of indicators, the main of which is the volume of erythrocytes (MCV). To establish why exactly blood hemoglobin decreases with a drop in MCV, it is necessary to determine the content of serum iron.

If the iron content is normal or even elevated, the patient is sent to a hematologist. If the iron is less than normal, then in order to find out why the hemoglobin has decreased, a differential diagnosis of iron deficiency anemia and anemia of chronic conditions is carried out. To do this, determine the level of blood transferrin.

Diagnostic algorithm for a decrease in hemoglobin

Iron deficiency anemia

Iron deficiency is registered in 30% of the world's population and in 6% of the European population. Almost half of these people have iron deficiency anemia (IDA). This type of anemia is the most common and accounts for 41.5% of all such conditions worldwide.data, and according to Russian scientists - 93%. Most often, IDA is registered in women, and almost half of the patients are between the ages of 15 and 30, with age the pathology is less common.

Iron deficiency anemia is a syndrome that is characterized by a violation of hemoglobin production due to iron deficiency, which develops against the background of various physiological and pathological conditions.

IDA is manifested by two groups of symptoms: anemic and sideropenic.

Anemic symptoms:

flies before the eyes, dizziness, tinnitus, darkening of the eyes when standing up quickly, headaches;
weakness, fatigue, decreased performance, fatigue;
pallor of the skin and mucous membranes, palpitations, shortness of breath on exertion, throbbing in the neck and temples.

Sideropenic symptoms:

Dry skin, dull, split ends.
Cracks on the feet, fingertips.
Fragility, layering, waviness of nails, nails become concave, shaped like a spoon.
Dark tooth enamel, caries.
Perversion of taste and smell. Often, patients mistake signs of iron deficiency for their quirks or personality traits. Eating earth, lime, chalk, raw meat, potatoes, paints, a constant desire to eat something cold - ice or ice cream, a love of the smell of kerosene, exhaust fumes, soap - are symptoms of low hemoglobin.
Glossitis (inflammation of the tongue), dysphagia (impaired swallowing), angular stomatitis (bites, cracks in the corners of the mouth).
Decreaseintellectual ability.
Tachycardia, diastolic myocardial dysfunction.
Inability to hold urine when laughing or coughing. Patients note the syndrome of "restless legs" - the need to move the legs due to the emerging sensation of discomfort, mainly in the evening.

Causes of iron deficiency

Blood loss. The most common reason why hemoglobin decreases in women is considered to be prolonged and heavy menstruation. It is the cause of a decrease in the iron content in the blood of women in 30% of all cases. If your period lasts more than 5 days or more often than every 26 days, your body will lose more than 60 ml of blood per month. Taking into account the loss of iron with this volume of blood and the moderate intake of this trace element from food, in 10 years the body will lose half of the total supply of iron. That is why blood hemoglobin decreases in women, mostly young women - before menopause.

5% of low iron is due to donation, 1% due to nosebleeds, another 1% due to loss in the urine, such as kidney stones.

The main reason why blood hemoglobin decreases in men and women is bleeding from the gastrointestinal tract. Such pathologies occur with ulcers, erosions, polyps, tumors, hemorrhoids, taking aspirin and other non-steroidal anti-inflammatory drugs (increase the blood permeability of the small intestine wall).

Congenital iron deficiency. It is registered in newborns in case of a lack of iron from the mother duringpregnancy.

Malabsorption. In 5% of cases, low iron levels are recorded due to intolerance to the gluten protein of cereals. This disease is called celiac disease, it leads to atrophy of the intestinal mucosa and, as a result, to malabsorption of substances, including iron. In Russia, this disease is often detected. In addition, negative taste preferences lead to malabsorption. Tea, coffee, foods rich in calcium (cheese, cream, cottage cheese, walnuts) - this is what can reduce hemoglobin.

Iron deficiency in food with strict diets or vegetarianism. Iron deficiency in mother's milk is a common cause of low hemoglobin in newborns.

Increased iron consumption noted during:

transitional age, mostly in girls;
pregnancy;
lactation;
premenopausal women.

The following norms and minimum levels of hemoglobin during pregnancy are adopted:

in I trimester: 112-160 110 g/l;
2nd trimester: 108-144 105g/l;
in III trimester: 112-140 110 g/l.

Why does hemoglobin decrease in women during pregnancy?

The first reason is an increase in whole blood volume. This happens due to an increase in the mostly liquid part of the blood, so the concentration of all blood substances decreases. This is physiological anemia.

The second reason why hemoglobin decreases during pregnancy is the increased consumption of iron. It is necessary for the formation of hematopoieticsystems of the fetus, for the synthesis of its hemoglobin, the formation of other tissues of the child, as well as for the construction of the placenta and the growth of the uterus. The highest consumption of iron occurs at 16-20 weeks of pregnancy. This explains why hemoglobin in pregnant women decreases precisely in the second trimester.

In addition, one should not exclude various pathological conditions that can lead to an even greater drop in the hemoglobin content in the blood of the expectant mother.

Treatment of iron deficiency anemia

Basic principles of treatment:

You can't cure iron deficiency anemia with diet. If the diagnosis is made, then the treatment is carried out only with iron preparations. Don't rely on proper nutrition. From food, only 2.5 mg per day can enter the body, with drugs - ten times more. It will be necessary to use products containing this microelement after its content in the blood is normal.
Must use oral medications.
Parenteral drug administration is reserved for severe cases of anemia, iron malabsorption or intolerance to oral medications.
The effectiveness of treatment is determined by the restoration of hemoglobin and iron levels (and not by the number of drugs taken).
For the treatment of iron deficiency anemia, ferric iron preparations are used. Currently, preparations of bi- and ferric iron are presented on the market. The latter are much more efficient and safer.

Anemia of chronic disease

This is the second most common type of anemia after iron deficiency. The reasons are more often:

chronic kidney disease;
chronic heart failure;
liver disease;
autoimmune diseases;
endocrine diseases (hypothyroidism, diabetes mellitus, hyperparathyroidism);
oncological diseases.

All of the above pathologies lead to a decrease in the life span of erythrocytes, inhibition of their synthesis and deposition of iron in the cells of the reticuloendothelial system. This explains why the hemoglobin content decreases in chronic diseases.

To treat anemia in chronic diseases, it is necessary to eliminate the underlying ailment. Iron supplements won't help.

Normocytic anemia

If a decrease in hemoglobin content is found in the blood, and the erythrocyte volume is normal, they speak of normocytic anemia. To find out the reason why hemoglobin decreases in this case, it is necessary to determine the content of reticulocytes. These are the precursor cells of red blood cells, they must mature in the red bone marrow, and then in the bloodstream into the red blood cells themselves. Normally, they contain 1% of all red blood cells in their blood. You can count them in a smear under a microscope. A high level of reticulocytes in the blood is caused by increased production of red blood cells in the red bone marrow and indicates the presence of post-hemorrhagic or hemolytic anemia.

Posthemorrhagic anemia can develop as a result of acute bleeding that requires surgicalintervention.

Hemolytic anemia is a pathological condition of the body caused by increased destruction of red blood cells. It can be hereditary and acquired, in half of the cases the cause of anemia is not established. Red blood cells can be destroyed by the following factors:

mechanical damage to the erythrocyte membrane (by heart valve prostheses, heart-lung machine);
chemical damage to red blood cells (snake bites, poisoning with lead, benzene, pesticides);
hypersensitivity to certain drugs;
parasitic infections (malaria).

For successful treatment, it is necessary to eliminate the cause of anemia. In addition, assign:

vitamin B preparations_{12 and folic acid;}
in special cases - transfusion of “washed” red blood cells;
glucocorticoid hormones, since the disease is often accompanied by an increase in the size of the spleen and liver (in some cases, the spleen is removed);
cytostatics in autoimmune etiology.

Hemolytic disease of the newborn

HDN refers to congenital hemolytic anemia.

Do not confuse HDN with physiological neonatal jaundice. Such jaundice occurs in most premature and half full-term babies without any pathology. The fact is that in the blood of a child before birth, a special fetal hemoglobin prevails, which has an increased ability to attach oxygen. While the baby is in the womb, the mother's blood supplies it with oxygen, it turns out to benot enough. In conditions of oxygen deficiency, ordinary hemoglobin would not be able to cope with its delivery to every cell of the fetal body. After birth, the child begins to breathe on his own, there is more oxygen, fetal hemoglobin is already unnecessary and is replaced by the usual "adult". After childbirth, "children's" hemoglobin begins to gradually break down in the vascular bed with the formation of the final product - bilirubin, which has a red-yellow color. That is why a child's hemoglobin decreases in the first two months of life from 200 to 140 g/l. Usually such jaundice goes away on its own, sometimes treatment with lamps is needed. More rarely, jaundice is caused by pathological causes that need to be diagnosed and treated.

One of these causes is hemolytic disease of the newborn, which occurs in 0.5% of children. It occurs due to the incompatibility of the blood of the mother and fetus. The cause may be the mother's Rh negative and the baby's positive, or their different blood types. As a result, the female body produces antibodies that destroy the fetal red blood cells. Despite the name - "disease of the newborn", the disease can affect the child in the womb and even lead to his death. The destruction of red blood cells leads to a state of anemia in the newborn and, in some cases, severe jaundice. This explains why hemoglobin decreases after TTH.

Macrocytic anemia

It is characterized by a violation of the process of hematopoiesis and the appearance in the vascular bed of large cells called macrocytes. Atdetection of such cells in a blood smear suggests B₁₂-deficient, folate-deficient, or drug-induced toxic anemia. Of these, B₁₂-deficient is more common, recorded mainly in the elderly. The lack of this vitamin occurs with the strictest vegetarianism, after operations on the stomach, small intestine, with stomach cancer, helminthic invasion. To treat this type of anemia, B_{12 drugs are prescribed at a dose of 500-1000 g / day and treatment of the pathology that causes vitamin deficiency.}

Folic deficiency anemia develops mainly in young people. Vitamin deficiency can be due to insufficient intake of plant foods, as well as inflammation of the small intestine or the removal of part of it. An increased need for the vitamin occurs during pregnancy. For treatment, folic acid is prescribed at a dosage of 5-15 mg / day.