Leukemias begin in a white blood cell in the bone marrow that undergoes a change to become a type of leukemia cell that then undergoes leukemic change – meaning the cells may grow and survive better than normal cells, crowding out or suppressing the normal cells. Depending on the type of disease, the rate at which leukemia progresses and how the cells replace the normal blood and marrow cells differs. In turn, the abnormal white blood cells are not able to fight infection and also impair the ability of the bone marrow to produce red blood cells and platelets.
Leukemia begins in the bone marrow and can spread to the blood, lymph nodes and spleen.
Leukemia can occur in both children and adults, for which symptoms can vary.