The feedback from low hemoglobin to blood tests means to suffer from anemia. Hemoglobin is critical to carry oxygen from peripheral blood to body tissues. The main ones causes of low hemoglobin they are macrocytic and iron deficiency anemias, hemoglobinopathies such as thalassemia and sickle cell anemia. The main symptoms of low hemoglobin are the skin paleness, fatigue, shortness of breath after small efforts.
The presence of low hemoglobin blood tests always arouse great concern, and it is a fairly frequent finding, being the most common alteration of the blood count. The causes of reduced hemoglobin they are manifold, and in most cases they are easily correctable. Often the drop in hemoglobin it is not accompanied by any specific symptoms, and is detected only after routine blood chemistry tests, such as those carried out on the recommendation of the employer. Let's analyze how hemoglobin works, and why we might find some low values in the blood.
Low hemoglobin values
Normal hemoglobin values are not the same for all people, as they differ based on gender, age, and special conditions such as pregnancy.
According to the criteria of the World Health Organization WHO, we speak of low hemoglobin values:
- In the adult men, when the hemblobin values are lower than i 13 g / dl (130 g / L), i.e. 13 grams per deciliter or 130 grams per liter.
- In the women non-pregnant adults, when the hemoglobin values are less than 12 g / dl (120 g / L), i.e. 12 grams per deciliter or 120 grams per liter.
- In the women pregnant adults, when the hemoglobin values are less than 11 g / dL (110 g / L), i.e. 11 grams per deciliter or 110 grams per liter.
- In the children aged 12 - 14, when the hemoglobin values are less than 12 g / dl (120 g / L), i.e. 12 grams per deciliter or 120 grams per liter.
- In the children aged 5 - 11 years, when the hemoglobin values are less than 11.5 g / dL (115 g / L), i.e. 11.5 grams per deciliter or 115 grams per liter.
- In the children aged 6 months to 5 years, when the hemoglobin values are less than 11 g / dL (110 g / L), i.e. 11 grams per deciliter or 110 grams per liter.
What is hemoglobin
What is hemoglobin?
Hemoglobin is a macromolecule contained in ours Red blood cells (also called erythrocytes or red blood cells). Hemoglobin is commonly abbreviated with the abbreviation Hb or with Hbg, and consists of 4 polypeptide chains of globin equal to two by two. The hemoglobin tetramer is in fact composed of two alpha chains and two beta chains, and is called HbA. This is the conformation most present in our body: other less represented variants of hemoglobin are the HbA2, consisting of two alpha chains and two gamma chains, and the HbS, that is thefetal hemoglobin, which is a predominant hemoglobin during the gestational period and the first months of life, which is then replaced by hemoglobin HbA in youth and adult life.
Each globin chain is linked with one protoporphyrin and to a molecule of iron, which constitute the “operative nucleus of the unit, which taken as a whole takes the name of heme.
The globin chains are by themselves insoluble in the blood, but joined together in the structure of hemoglobin (hemoglobin tetramer) become ad high solubility. This is good, as single unpaired chains could form agglomerations called i Heinze bodies, precipitate inside the red blood cells e damage the erythrocyte. To avoid this, our body always tries to produce a balanced quantity of hemoglobin chains.
How hemoglobin works
Hemoglobin works in the bloodstream, absorbing oxygen present in our pulmonary alveoli, tying it to if and carrying it up to the peripheral tissues where it is released. There are some factors that enhance or weaken the ability ofhemoglobin to bind oxygen: for example, the acidity of the blood (expressed by low pH values) facilitates assignment of oxygen from hemoglobin to tissues. This is a fundamental mechanism, because in oxygen-deprived tissues, where energy is produced with anaerobic mechanism releasing lactic acid, the pH will be reduced, and hemoglobin will be facilitated to release oxygen molecules precisely in the areas that need it most.
Low hemoglobin causes
What are the main causes of Low HGB? The finding of a reduction in hemoglobin values is quite frequent in blood tests. There are women who spend most of the years of their life with lower than normal hemoglobin levels. Having said that, however, a drop in hemoglobin can be the alarm bell of an underlying disease, and it must be investigated promptly to recognize the cause and establish a possible treatment. The main ones causes of low hemoglobin I'm:
- Hypoproliferative anemia
- Iron deficiency anemia (microcytic anemia): characterized by small red blood cells, it develops in the presence of low iron in the blood (iron deficiency is also called iron deficiency). The main causes of iron deficiency are inadequate intake with food, reduced intestinal absorption or increased loss, sepsis linked to chronic gastrointestinal bleeding or heavy menstruation.
- Chronic inflammation / infection anemia
- Renal failure anemia
- Malnutrition anemia
- Anemia secondary to cirrhosis
- Endocrine deficiency anemia
- Alpha thalassemia
- Beta thalassemia or Mediterranean anemia: it is distinguished in beta thalassemia major or Cooley's disease in which both genes that synthesize hemoglobin are mutated, and thalassemia minor or thalassemia trait, in which only one allele has changed.
- Sickle cell anemia
- Structural thalassemic variants such as hemoglobin Lepore, hemoglobin E or congenital persistence of fetal hemoglobin HbF
- Carbon monoxide poisoning
- Megaloblastic anemia (macrocytic anemia):
- Pernicious anemia
- Poor absorption I have reduced intake of vitamin B12 and / or folic acid (folate)
- Use of drugs that alter DNA metabolism and therefore the synthesis of red blood cells (methotrexate, sulfonamides such as sulfasalazine and many others)
- Low hemoglobin in pregnancy: often, in pregnancy, hemoglobin levels are found a little lower than normal, so much so that even the normal values of hemoglobin in pregnancy have been corrected by lowering the references a little. Anemia in pregnancy has multiple causes, including a greater amount of body fluids that dilute the substances present in the blood, a lack of iron, which is common during pregnancy, and a reduction in absorption and a greater consumption of vitamin B12 and folate.
- Hemolytic anemias
- Autoimmune hemolytic anemia
- Paroxysmal nocturnal hemoglobinuria
- Acanthocyte anemia
- Hereditary spherocytosis anemia
- Microangiopathic hemolysis anemia
- Disseminated intravascular coagulation
- Favism, G6PD deficiency
- Cryoagglutinin diseases cryoglobulinemia
- Thrombotic thrombocytopenic purpura and haemolytic uremic syndrome
- Prosthetic hemolysis, for example in the presence of mechanical heart valve prostheses
- Anemia secondary to drugs
- Anemia due to reduced bone marrow synthesis
- Aplastic anemia
- Myelodysplasias (more correctly called myelodysplastic syndromes)
- Fanconi anemia
- Increased loss anemias
- Acute hemorrhage anemia
- Chronic bleeding anemia
- Menorrhagia anemia, i.e. secondary to heavy menstruation
- Hemodilution anemia: they are all those anasarcatic states characterized by the presence of a large amount of liquids in the body tissues, which lead to a dilution of the substances dissolved in the blood including hemoglobin.
Low hemoglobin symptoms
But what symptoms to expect in the presence of reduced hemoglobin values? Some symptoms are fairly obvious others are a little more subtle. In general, the clinical manifestations that can be observed or perceived in parallel with the finding of a reduction in hemoglobin values are symptoms of anemia. Furthermore, some pathologies have specific symptoms which are those of the pathology that has caused, among other things, a reduction in hemoglobin values. For example, in the presence of iron deficiency anemia, the symptoms could be very different from vitamin B12 deficiency anemia, as the underlying pathology is different.
Let's see the main ones together symptoms of low hemoglobin
- Skin pallor
- Nail pallor
- Conjunctival pallor
- Asthenia (tiredness, weakness)
- Fainting (syncope)
- Shortness of breath after modest efforts
- Reduced tolerance to cold
- Signs of bleeding in the case of post-haemorrhagic anemia,
- Melena, i.e. black stools due to the presence of old blood, a sign of bleeding in the upper digestive tract
- Rectorrhagia, that is, abundant bright red bleeding with the stool
- Hematochezia, i.e. stool minimally streaked with bright red blood
- Epistaxis, which is the common bleeding from the nose
- Gingivorrhagia, bleeding from the gums
- Hemoftoe, that is, the emission of blood from the respiratory tract with coughing
- Painful seizures in the presence of sickle cell anemia due to peripheral vascular microocclusions, with secondary ischemia causing widespread acute pain
- Cutaneous jaundice, caused by the increase of bilirubin in the blood, due to the massive destruction of hemoglobin such as occurs in haemolytic crises or in the acute phases of paroxysmal nocturnal hemoglobinuria
- Chest pain: Discrepancy infarcts are not uncommon, which are cardiac ischemias of varying magnitude secondary to reduced oxygen supply to the coronary arteries caused by low blood hemoglobin levels.
From the point of view of laboratory analysis, reduced hemoblobin is often accompanied by other blood count changes such as
- an alteration of the Red blood cells (for example: high red blood cells in the case of thalassemia trait, low erythrocytes in the case of acute or chronic blood loss anemia)
- an alteration of the mean corpuscular volume or MCV: High MCV in case of megaloblastic anemia, low MCV in case of iron deficiency microcytic anemia
- an alteration of theRDW (Red Cell Distribution Width), i.e. the variability of the volume of red blood cells: often in the presence of more than one cause of anemia, red blood cells of very different sizes coexist in the circulation, causing a concomitant finding of high RDW.
- An alteration of theMCHC, that is of the average cellular concentration of hemoglobin (in English mean corpuscular hemoglobin concentration): obviously in the presence of reduced hemoblobin, we will also have low MCHC.
Low hemoglobin risks
Which ones are they risks is consequences a reduction in hemoglobin?
First of all, we need to distinguish the timing of the drop in hemoglobin. In case theLow Hb is secondary to an acute cause, such as a hemorrhage or a crisis of haemolytic anemia, the loss of even a few points of hemoglobin will be enough to induce tangible symptoms. On the contrary, in the presence of a constant but minor loss of hemoglobin, such as in a chronic bleeding in a patient using anticoagulant drugs or in a woman with heavy menstruation, the human body has more time to get used to, and therefore they are tolerated. very low hemoglobin values without showing any signs or symptoms.
The main consequences of a reduction in circulating hemoglobin are related to the reduction of oxygen supply to body tissues. For example, the ability to carry out physical exertion is reduced, and people who even a moderate degree of arterial atherosclerosis could experience ischemic problems such as ischemia in the heart or in other parts of the body. Another example is frequent fainting, caused by a momentary under-flow of blood and oxygen to the brain.
Low hemoglobin remedies
But what to do in the presence of low hemoglobin? The first thing to do is to contact your general practitioner to another doctor to whom we have entrusted the care of our health. Your doctor will evaluate your symptoms' hemoglobin levels, and decide if you need to resort to one transfusion of blood or if it is possible to wait for hemoglobin levels to return to within 1 hour after the cause of the anemia is recognized and treated. values of reference. In this second case, surely the first things to do will be a careful medical history (which is the past and present medical history) and a thorough physical examination.
Secondly, in addition toblood count (including red blood cell count, hemoglobin, MCV, white blood cells and leukocyte formula, platelets), which we would have already performed, it will be essential to add other blood tests such as renal function (creatinine, urea, sodium and potassium), the indices of hepatic cytolysis and cholestasis (transaminase, GGT, alkaline phosphatase), direct and indirect bilirubin, the protein profile including albumin and total proteins, inflammation indices such as ESR and C reactive protein, and a urine test. Once these investigations have been carried out, the picture will certainly be a little clearer, since most anemia with reduced hemoglobin has a simple origin to identify.
Low hemoglobin: what to eat?
Often, in the presence of low hemoglobin values in the blood, one wonders if something in our diet is not correct. Undoubtedly, a varied and complete diet helps reduce the chances of developing deficiency anemia. For example, the intake of iron-rich foods, such as legumes, spinach, cocoa and chocolate, red meats, shellfish can help maintain iron stores (ferritin) and the concentration of circulating iron (sideremia) within the norm. A diet rich in fruit and vegetables and low in alcohol, on the other hand, can help to provide our body with an adequate amount of cyanocobalamin (vitamin B12) and folate (folic acid).
Tags: Laboratory medicine Blood