What does low hemoglobin mean?
Red blood cells deliver oxygen to all tissues, and hemoglobin inside them binds and releases this oxygen. When there is little hemoglobin, tissues receive less oxygen, and the body compensates for this by increasing heart rate and breathing. While the compensation is working, the person only feels fatigue; when it is not enough, shortness of breath appears during normal exertion, dizziness and palpitations. Based on the size of red blood cells and the hemoglobin content in them, the laboratory suggests the direction of the search: small pale cells are typical for iron deficiency, large ones for a lack of vitamin B12 and folic acid.
- Iron deficiency anemia is the most common
- Anemia of chronic diseases due to inflammation and tumors
- B12 and folate deficiency anemia
- Hemolytic anemia with accelerated destruction of red blood cells
- Anemia in kidney disease
- Aplastic anemia and bone marrow diseases
- Hereditary forms, such as thalassemia
Causes and risk factors
In women of childbearing age, the leading causes are heavy menstruation and pregnancy, during which the need for iron increases sharply. In men and women after menopause, low hemoglobin almost always requires a search for the source of blood loss in the gastrointestinal tract. Iron absorption is impaired by gastritis with low acidity, celiac disease, surgery on the stomach and intestines, and H. pylori infection. Vitamin B12 deficiency is characteristic of strict vegetarian diets, atrophic gastritis and old age. A separate group consists of anemia in chronic kidney disease, rheumatic diseases and oncology.
- Heavy menstruation and uterine bleeding
- Hidden blood loss from ulcers, polyps, intestinal tumors
- Pregnancy and breastfeeding
- Vegetarianism and unbalanced nutrition
- Celiac disease, atrophic gastritis, gastrointestinal surgery
- Chronic kidney disease
- Chronic inflammatory and oncological diseases
- Taking drugs that damage the gastric mucosa
Symptoms
Complaints depend not so much on the hemoglobin number, but on the rate of its decline. With slow development, the body adapts, and a person lives for years with a feeling of chronic fatigue. With rapid blood loss, even a moderate decrease causes severe weakness, dizziness and rapid heartbeat. Pallor of the skin and mucous membranes, brittle nails, hair loss, and congestion in the corners of the mouth are typical. A characteristic sign of iron deficiency is a perversion of taste and smell: a craving for chalk, ice, raw cereals, and the smell of gasoline. In older people, anemia may manifest itself as increased angina and shortness of breath.
- Weakness and fatigue
- Dizziness and tinnitus
- Shortness of breath and palpitations on exertion
- Pale skin and mucous membranes
- Brittle nails and hair, seizures
- Perversion of taste and smell
- Frozenness and decreased performance
- Decreased concentration
Diagnostics
The examination begins with a general blood test: it confirms anemia and, based on the characteristics of red blood cells, sets the direction of the search. Ferritin reflects iron stores and remains a key test, but increases with inflammation, so it is looked at together with C-reactive protein. For large red blood cells, vitamin B12 and folic acid are checked. If there is no obvious reason, a mandatory step is to search for the source of blood loss: stool analysis for occult blood, gastroscopy and colonoscopy, and in women, an examination by a gynecologist. If there is an unusual blood picture, the patient is referred to a hematologist.
- Complete blood count with erythrocyte indices and ESR
- Ferritin, serum iron, iron binding capacity
- Vitamin B12 and folic acid
- C-reactive protein
- Reticulocytes to assess bone marrow function
- Feces for occult blood
- Gastroscopy and colonoscopy for suspected blood loss
- Ultrasound of the abdominal cavity and pelvis
Treatment and prevention
Treatment is always twofold: replenishing the deficiency and eliminating the cause. For iron deficiency, oral iron supplements are prescribed; hemoglobin usually begins to increase after 2–4 weeks, but treatment is continued for another 2–3 months after normalization in order to fill the depot. Intravenous iron is used for intolerance to tablets, impaired absorption and the need for a quick effect. For B12 deficiency, the vitamin is used by injection or high doses orally. Blood transfusion is indicated only for severe life-threatening anemia. Nutrition helps maintain results, but does not replace treatment.
- Iron supplements in a course with controlled tests
- Continued use for 2–3 months after hemoglobin normalization
- Intravenous iron as prescribed by a physician
- Vitamin B12 and folic acid for deficiency
- Treatment of the source of blood loss
- Meat, liver, fish and foods with vitamin C in the diet
- Do not take iron supplements with tea, coffee or milk
- Monitoring blood tests during pregnancy and heavy menstruation