Hemoglobin failure, or abnormal hemoglobin (such as that of sickle-cell disease). The ability of each hemoglobin molecule to carry oxygen is normally modified by altered blood pH or CO, causing an altered oxygen–hemoglobin dissociation curve. However, it can also be pathologically altered in, e.g., carbon monoxide poisoning. Decrease of hemoglobin, with or without an absolute decrease of red blood cells, leads to symptoms of anemia. Anemia has many different causes, although iron deficiency and its resultant iron deficiency anemia are the most common causes in the Western world. As absence of iron decreases heme synthesis, red blood cells in iron deficiency
Glycated hemoglobin Glycated hemoglobin Glycated hemoglobin (hemoglobin A1c, HbA1c, A1C, or less commonly HgbA1c, haemoglobin A1c, HbA, Hb1c, etc.) is a form of hemoglobin that is bound to glucose. It is formed in a non-enzymatic glycation pathway by hemoglobin's exposure to plasma glucose. It is measured primarily to identify the three-month average plasma glucose concentration and thus can be used as a diagnostic test for diabetes and as assessment test for glycemic control in people with diabetes. The test is limited to a three-month average because the lifespan of a red blood cell is four months (120 days). However, since red blood