Hemoglobin is a protein containing iron that facilitates the transport of oxygen in red blood cells. Almost all vertebrates contain hemoglobin, with the exception of the fish family Channichthyidae and the tissues of some invertebrate animals. Hemoglobin in the blood carries oxygen from the respiratory organs to the other tissues of the body, where it releases the oxygen to enable aerobic respiration which powers the animal's metabolism. A healthy human has 12 to 20 grams of hemoglobin in every 100 mL of blood. Hemoglobin is a metalloprotein, a chromoprotein, and globulin.
Anemia or anaemia is a blood disorder in which the blood has a reduced ability to carry oxygen due to a lower than normal number of red blood cells, a reduction in the amount of hemoglobin or hemoglobin abnormalities. The name is derived from Ancient Greek: ἀναιμία anaimia, meaning 'lack of blood', from ἀν- an-, 'not' and αἷμα haima, 'blood'. When anemia comes on slowly, the symptoms are often vague, such as tiredness, weakness, shortness of breath, headaches, and a reduced ability to exercise. When anemia is acute, symptoms may include confusion, feeling like one is going to pass out, loss of consciousness, and increased thirst. Anemia must be significant before a person becomes noticeably pale. Symptoms of anemia depend on how quickly hemoglobin decreases. Additional symptoms may occur depending on the underlying cause. Preoperative anemia can increase the risk of needing a blood transfusion following surgery. Anemia can be temporary or long term and can range from mild to severe.
A complete blood count (CBC), also known as a full blood count (FBC), is a set of medical laboratory tests that provide information about the cells in a person's blood. The CBC indicates the counts of white blood cells, red blood cells and platelets, the concentration of hemoglobin, and the hematocrit. The red blood cell indices, which indicate the average size and hemoglobin content of red blood cells, are also reported, and a white blood cell differential, which counts the different types of white blood cells, may be included.
Hereditary spherocytosis (HS) is a congenital hemolytic disorder, wherein a genetic mutation coding for a structural membrane protein phenotype leads to a spherical shaping of erythrocytic cellular morphology. As erythrocytes are sphere-shaped (spherocytosis), rather than the normal biconcave disk-shaped, their morphology interferes with these cells' abilities to be flexible during circulation throughout the entirety of the body - arteries, arterioles, capillaries, venules, veins, and organs. This difference in shape also makes the red blood cells more prone to rupture under osmotic and/or mechanical stress. Cells with these dysfunctional proteins are degraded in the spleen, which leads to a shortage of erythrocytes resulting in hemolytic anemia.
Iron-deficiency anemia is anemia caused by a lack of iron. Anemia is defined as a decrease in the number of red blood cells or the amount of hemoglobin in the blood. When onset is slow, symptoms are often vague such as feeling tired, weak, short of breath, or having decreased ability to exercise. Anemia that comes on quickly often has more severe symptoms, including confusion, feeling like one is going to pass out or increased thirst. Anemia is typically significant before a person becomes noticeably pale. Children with iron deficiency anemia may have problems with growth and development. There may be additional symptoms depending on the underlying cause.
The mean corpuscular hemoglobin concentration (MCHC) is a measure of the concentration of hemoglobin in a given volume of packed red blood cell.
The mean corpuscular volume, or mean cell volume (MCV), is a measure of the average volume of a red blood corpuscle. The measure is obtained by multiplying a volume of blood by the proportion of blood that is cellular, and dividing that product by the number of erythrocytes in that volume. The mean corpuscular volume is a part of a standard complete blood count.
Red blood cell distribution width (RDW), as well as various types thereof, is a measure of the range of variation of red blood cell (RBC) volume that is reported as part of a standard complete blood count. Red blood cells have an average volume of 80–100 femtoliters, but individual cell volumes vary even in healthy blood. Certain disorders, however, cause a significantly increased variation in cell size. Higher RDW values indicate greater variation in size. Normal reference range of RDW-CV in human red blood cells is 11.5–15.4%. If anemia is observed, RDW test results are often used together with mean corpuscular volume (MCV) results to determine the possible causes of the anemia. It is mainly used to differentiate an anemia of mixed causes from an anemia of a single cause.
Megaloblastic anemia is a type of macrocytic anemia. An anemia is a red blood cell defect that can lead to an undersupply of oxygen. Megaloblastic anemia results from inhibition of DNA synthesis during red blood cell production. When DNA synthesis is impaired, the cell cycle cannot progress from the G2 growth stage to the mitosis (M) stage. This leads to continuing cell growth without division, which presents as macrocytosis. Megaloblastic anemia has a rather slow onset, especially when compared to that of other anemias. The defect in red cell DNA synthesis is most often due to hypovitaminosis, specifically vitamin B12 deficiency or folate deficiency. Loss of micronutrients may also be a cause.
Microcytic anaemia is any of several types of anemia characterized by smaller than normal red blood cells. The normal mean corpuscular volume is approximately 80–100 fL. When the MCV is <80 fL, the red cells are described as microcytic and when >100 fL, macrocytic. The MCV is the average red blood cell size.
Sideroblastic anemia, or sideroachrestic anemia, is a form of anemia in which the bone marrow produces ringed sideroblasts rather than healthy red blood cells (erythrocytes). In sideroblastic anemia, the body has iron available but cannot incorporate it into hemoglobin, which red blood cells need in order to transport oxygen efficiently. The disorder may be caused either by a genetic disorder or indirectly as part of myelodysplastic syndrome, which can develop into hematological malignancies.
The Mentzer index, described in 1973 by William C. Mentzer, is the MCV divided by the RBC count. It is said to be helpful in differentiating iron deficiency anemia from beta thalassemia trait.
Hypochromic anemia is a generic term for any type of anemia in which the red blood cells are paler than normal. A normal red blood cell has a biconcave disk shape and will have an area of pallor in its center when viewed microscopically. In hypochromic cells, this area of central pallor is increased. This decrease in redness is due to a disproportionate reduction of red cell hemoglobin in proportion to the volume of the cell. Clinically the color can be evaluated by the mean corpuscular hemoglobin (MCH) or mean corpuscular hemoglobin concentration (MCHC). The MCHC is considered the better parameter of the two as it adjusts for effect the size of the cell has on its amount of hemoglobin. Hypochromia is clinically defined as below the normal MCH reference range of 27–33 picograms/cell in adults or below the normal MCHC reference range of 33–36 g/dL in adults.
Anisocytosis is a medical term meaning that a patient's red blood cells are of unequal size. This is commonly found in anemia and other blood conditions. False diagnostic flagging may be triggered on a complete blood count by an elevated WBC count, agglutinated RBCs, RBC fragments, giant platelets or platelet clumps. In addition, it is a characteristic feature of bovine blood.
Red blood cell indices are blood tests that provide information about the hemoglobin content and size of red blood cells. Abnormal values indicate the presence of anemia and which type of anemia it is.
Microcytosis or microcythemia is a condition in which red blood cells are unusually small as measured by their mean corpuscular volume.
Normocytic anemia is a type of anemia and is a common issue that occurs for men and women typically over 85 years old. Its prevalence increases with age, reaching 44 percent in men older than 85 years. The most common type of normocytic anemia is anemia of chronic disease.
Iron tests are groups of clinical chemistry laboratory blood tests that are used to evaluate body iron stores or the iron level in blood serum.
Non-sideropenic hypochromic anemia also known as Normochromic Normocytic Anemia is a kind of anemia in which the red blood cells in circulation have a normal red color (normochromic) and the same size (normocytic). Normocytic normochromic anemia is most commonly caused by a variety of chronic infections and systemic diseases.
Anemia is a condition in which blood has a lower-than-normal amount of red blood cells or hemoglobin. Anemia in pregnancy is a decrease in the total red blood cells (RBCs) or hemoglobin in the blood during pregnancy. Anemia is an extremely common condition in pregnancy world-wide, conferring a number of health risks to mother and child. While anemia in pregnancy may be pathologic, in normal pregnancies, the increase in RBC mass is smaller than the increase in plasma volume, leading to a mild decrease in hemoglobin concentration referred to as physiologic anemia. Maternal signs and symptoms are usually non-specific, but can include: fatigue, pallor, dyspnea, palpitations, and dizziness. There are numerous well-known maternal consequences of anemia including: maternal cardiovascular strain, reduced physical and mental performance, reduced peripartum blood reserves, increased risk for peripartum blood product transfusion, and increased risk for maternal mortality.
