Editing Leukemia (section)

===General classification===
Clinically and pathologically, leukemia is subdivided into a variety of large groups. The first division is between its ''[[Acute (medical)|acute]]'' and ''[[chronic (medicine)|chronic]]'' forms:<ref name=":1">{{Cite web |title=Questions and Answers About Leukemia |url=https://www.cdc.gov/nceh/radiation/phase2/mleukemi.pdf |url-status=live |archive-url=https://web.archive.org/web/20210730115224/https://www.cdc.gov/nceh/radiation/phase2/mleukemi.pdf |archive-date=July 30, 2021 |access-date=August 8, 2021 |website=[[Centers for Disease Control and Prevention]]}}</ref>
* [[Acute leukemia]] is characterized by a rapid increase in the number of immature blood cells. The crowding that results from such cells makes the bone marrow unable to produce healthy blood cells resulting in low [[hemoglobin]] and low [[platelet]]s. Immediate treatment is required in acute leukemia because of the rapid progression and accumulation of the [[malignant cell]]s, which then spill over into the bloodstream and spread to other organs of the body. Acute forms of leukemia are the most common forms of [[childhood leukemia|leukemia in children]].
* [[Chronic leukemia]] is characterized by the excessive buildup of relatively mature, but still abnormal, [[white blood cell]]s (or, more rarely, [[red blood cell]]s). Typically taking months or years to progress, the cells are produced at a much higher rate than normal, resulting in many abnormal white blood cells. Whereas acute leukemia must be treated immediately, chronic forms are sometimes monitored for some time before treatment to ensure maximum effectiveness of therapy. Chronic leukemia mostly occurs in older people but can occur in any age group.

Additionally, the diseases are subdivided according to which kind of blood cell is affected. This divides leukemias into [[Acute lymphoblastic leukemia|lymphoblastic]] or ''[[lymphocytic leukemia]]s'' and [[Myeloid leukemia|myeloid]] or ''[[myelogenous leukemia]]s'':<ref name=":1" />
* In lymphoblastic or [[lymphocytic leukemia]]s, the cancerous change takes place in a type of marrow cell that normally goes on to form [[lymphocyte]]s, which are infection-fighting immune system cells. Most lymphocytic leukemias involve a specific subtype of lymphocyte, the [[B&nbsp;cell]].
* In myeloid or [[myelogenous leukemia]]s, the cancerous change takes place in a [[myeloid cells|type of marrow cell]] that normally goes on to form [[red blood cell]]s, some other types of white cells, and [[platelet]]s.

Combining these two classifications provides a total of four main categories. Within each of these main categories, there are typically several subcategories. Finally, some rarer types are usually considered to be outside of this classification scheme.<ref name=":1" /><ref>{{Cite web|title=Leukemia — Symptoms and causes|url=https://www.mayoclinic.org/diseases-conditions/leukemia/symptoms-causes/syc-20374373|access-date=2021-08-08|website=Mayo Clinic|language=en}}</ref>