- Anaemia | A condition in which blood haemoglobin concentration is below normal. Normal values are 12g/dl for women and 14 g/dl for men.
- Anaemia of chronic disease (ACD) | Anaemia that arises in association with infection, malignancy, malnutrition, or chronic inflammatory disorders. This form of anaemia usually affects older patients and is driven by systemic inflammation.
- Anaemia of chronic inflammation | Anaemia of chronic disease (ACD) that occurs in patients with chronic inflammatory disease, autoimmune conditions , cancer; it is defined by low serum iron (< 60 µg/dl) with normal or increased serum ferritin levels.
- Anaemia of chronic kidney disease | Anaemia directly resulting from an impairment of erythropoietin production due to kidney disease, leading to a hypo-regenerative anaemia.
- Aplastic anaemia | A rare, severe form of anaemia characterised by peripheral pancytopenia and cellular hypoplasia of the bone marrow. In the majority of cases it is idiopathic, but diverse known causes (drug, virus and radiation exposure) are recognised.
- Carboxyhaemoglobin (COHb) | A stable complex of carbon monoxide and haemoglobin that forms in erythrocytes when carbon monoxide is inhaled (usually by cigarette smoking). COHb has a 200-fold affinity to haemoglobin and therefore blocks the haemoglobin molecules, impairing the delivery of oxygen to the body.
- Erythrocytes (red blood cells) | The most common type of blood cell and the body's principal means of delivering oxygen to the tissues.
- Erythropoiesis | The process by which erythrocytes are produced. It is stimulated by decreased oxygen in circulating blood, which is detected by the kidneys, and occurs in the bone marrow of large bones.
- Erythropoietin (EPO) | A glycoprotein hormone that controls erythropoiesis. Produced in the kidney upon hypoxic stimulation.
- Folate deficiency | Frequently implicated in anaemia in older patients, the most common cause is medication with folate antagonists (e.g. methotrexate, cotrimoxazole, antiepileptics) or inadequate dietary intake. Results in macrocytic anaemia.
- Haemoglobin (Hb) | The iron-containing oxygen-transport metalloprotein in erythrocytes.
- Haemolysis | Reduced erythrocyte survival time by abnormal breakdown either in the blood vessels (intravascular) or elsewhere in the human body (extravascular).
- Haemolytic anaemia | A form of anaemia caused by decreased erythrocyte survival time. Haemolytic anaemias are subdivided into corpuscular origin (e.g. spherocytosis, elliptocytosis) and non-corpuscular origin (e.g. enzymatic defects, autoimmune antibody formation).
- Hyperregenerative anaemia | Anaemia in which the bone marrow responds appropriately to a low erythrocyte mass by increasing production of reticulocytes.
- Hypo-regenerative anaemia | Anaemia characterised by a decrease in the production of reticulocytes.
- Macrocytic anaemia | Anaemia that is characterized by above-average sized erythrocytes (mean corpuscular volume >98 fl). May result from B12 vitamin and folate deficiency, hyper-regenerative haemolytic anaemia, and myelodysplasia.
- Mean corpuscular volume (MCV) | A measure of the average erythrocyte size that is reported as part of a standard complete blood count. Calculated by dividing the total number of packed red blood cells (haematocrit) by the total number of erythrocytes.
- Megaloblastic anaemia | A form of macrocytic anaemia that results from inhibition of DNA synthesis in red blood cell precursors. Most often due to deficiency of vitamin B12 and/or folic acid.
- Microcytic anaemia | Anaemia that is characterised by below-average sized erythrocytes (mean corpuscular volume < 82 fl). May occur in iron-deficiency, thalassaemia and anaemia of chronic disease.
- Myelodysplastic syndromes | A heterogeneous group of neoplastic diseases characterised by peripheral cytopenias, usually hypercellular bone marrow and a propensity to transform into acute leukaemias.
- Normocytic anaemia | Anaemia with normal-sized erythrocytes (mean corpuscular volume 82–98 fl). May be caused by combined nutritional deficiency, renal failure, mild haemolytic anaemia, anaemia of chronic disease, acute bleeding, leukaemias or metastasis of solid cancer to the bone marrow.
- Nutrient-deficiency anaemia | Anaemia due to a lack of iron, and/or folate, and/or vitamin B12. May result from dietary deficiency (iron, B12 and folate deficiency), leading to a hypo-regenerative anaemia, or from acute/chronic bleeding (iron deficiency), leading to a hyper-regenerative anaemia.
- Reticulocytes | Immature red blood cells that develop and mature in the bone marrow and then circulate for about a day in the blood stream before developing into mature red blood cells (erythrocytes).
- Sideroblastic anaemia | A disease in which abnormal, ringed sideroblasts are produced. These are erythroblasts characterized by an accumulation of iron in mitochondria. May be caused either by a congenital genetic disorder or by an acquired genetic disorder during myelodysplastic syndrome.
- Thalassaemias | A group of inherited haematological disorders caused by defects in the synthesis of one or more of the haemoglobin chains. Imbalances of globin chains can cause haemolysis and ineffective erythropoiesis.
- Vitamin B12 (cobalamin) deficiency | Frequently implicated in anaemia in older patients, the most common cause is food-cobalamin malabsorption with or without autoimmune causes (pernicious anaemia). Results in macrocytic anaemia.