<unk>  is a type of macrocytic<unk> . An<unk>  is a red blood cell defect that can lead to an undersupply of oxygen.<unk>  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.<unk>  has a rather slow onset, especially when compared to that of other<unk> s. 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.<unk>  not due to hypovitaminosis may be caused by antimetabolites that poison DNA production directly, such as some chemotherapeutic or antimicrobial agents (for example azathioprine or trimethoprim). The pathological state of megaloblastosis is characterized by many large immature and dysfunctional red blood cells (megaloblasts) in the bone marrow and also by hypersegmented neutrophils (defined as the presence of neutrophils with six or more lobes or the presence of more than 3% of neutrophils with at least five lobes). These hypersegmented neutrophils can be detected in the peripheral blood (using a diagnostic smear of a blood sample).
Megaloblastic anemia
Normocytic anemia
Normochromic anemia
Pythiosis
Osteomalacia
Agranulocytosis
Hypochromic anemia
Lathyrism