[2] Symptoms may include bleeding and bruising, bone pain, fatigue, fever, and an increased risk of infections.

[5] Risk factors include smoking, ionizing radiation, petrochemicals (such as benzene), prior chemotherapy, and Down syndrome.

[4] In children under 15 in first-world countries, the five-year survival rate is greater than 60% or even 90%, depending on the type of leukemia.

The first division is between its acute and chronic forms:[15] Additionally, the diseases are subdivided according to which kind of blood cell is affected.

This could cause the person's immune system to be unable to fight off a simple infection or to start attacking other body cells.

Some people experience nausea or a feeling of fullness due to an enlarged liver and spleen; this can result in unintentional weight loss.

Blasts affected by the disease may come together and become swollen in the liver or in the lymph nodes causing pain and leading to nausea.

[39] If the leukemic cells invade the central nervous system, then neurological symptoms (notably headaches) can occur.

Uncommon neurological symptoms like migraines, seizures, or coma can occur as a result of brain stem pressure.

Certain mutations can trigger leukemia by activating oncogenes or deactivating tumor suppressor genes, and thereby disrupting the regulation of cell death, differentiation or division.

[45] Among adults, the known causes are natural and artificial ionizing radiation and petrochemicals, notably benzene and alkylating chemotherapy agents for previous malignancies.

[46] Cohort and case-control studies have linked exposure to some petrochemicals and hair dyes to the development of some forms of leukemia.

The International Agency for Research on Cancer expert working group undertook a detailed review of all data on static and extremely low frequency electromagnetic energy, which occurs naturally and in association with the generation, transmission, and use of electrical power.

[60] They concluded that there is limited evidence that high levels of ELF magnetic (but not electric) fields might cause some cases of childhood leukemia.

[61] Diagnosis is usually based on repeated complete blood counts and a bone marrow examination following observations of the symptoms.

[62] Following diagnosis, blood chemistry tests can be used to determine the degree of liver and kidney damage or the effects of chemotherapy on the person.

These can potentially show leukemia's effects on such body parts as bones (X-ray), the brain (MRI), or the kidneys, spleen, and liver (ultrasound).

Additionally, treatment must prevent leukemic cells from spreading to other sites, particularly the central nervous system (CNS); periodic lumbar punctures are used for diagnostic purposes and to administer intrathecal prophylactic methotrexate.

The use of a corticosteroid has the additional benefit of suppressing some related autoimmune diseases, such as immunohemolytic anemia or immune-mediated thrombocytopenia.

Younger and healthier people may choose allogeneic or autologous bone marrow transplantation in the hope of a permanent cure.

[71] Decision to treat People with hairy cell leukemia who are symptom-free typically do not receive immediate treatment.

Alemtuzumab (Campath), a monoclonal antibody that attacks white blood cells, has been used in treatment with greater success than previous options.

[13] Outcomes depend on whether it is acute or chronic, the specific abnormal white blood cell type, the presence and severity of anemia or thrombocytopenia, the degree of tissue abnormality, the presence of metastasis and lymph node and bone marrow infiltration, the availability of therapies and the skills of the health care team.

Around ten years after Virchow's findings, pathologist Franz Ernst Christian Neumann found that the bone marrow of a deceased person with leukemia was colored "dirty green-yellow" as opposed to the normal red.

This finding allowed Neumann to conclude that a bone marrow problem was responsible for the abnormal blood of people with leukemia.

By 1947, Boston pathologist Sidney Farber believed from past experiments that aminopterin, a folic acid mimic, could potentially cure leukemia in children.

[92] According to Susan Sontag, leukemia was often romanticized in 20th-century fiction, portrayed as a joy-ending, clean disease whose fair, innocent and gentle victims die young or at the wrong time.

[96] Studies may focus on effective means of treatment, better ways of treating the disease, improving the quality of life for people, or appropriate care in remission or after cures.

Clinical/translational research focuses on studying the disease in a defined and generally immediately applicable way, such as testing a new drug in people.

[105] Acute leukemias normally require prompt, aggressive treatment, despite significant risks of pregnancy loss and birth defects, especially if chemotherapy is given during the developmentally sensitive first trimester.