Leukemia is a cancer of the body’s blood – forming tissues in which are included the lymphatic system and bone marrow. There are many different types of leukemia that exist. It is noticed that some forms of leukemia are more common in children. There are other forms of leukemia which can happen mostly in adults. Usually, leukemia involves the white blood cells. The white blood cells are potent infection fighters and they normally grow and divide in an orderly way, as the body needs them.
But in people who suffer from leukemia, the bone marrow is producing abnormal white blood cells which do not function properly. The treatment for leukemia can be complex, which depends on the type of leukemia and other factors. But there are some resources and strategies which can make the treatment of leukemia successful.
The symptoms of leukemia vary which depends on the type of leukemia that you have . The most common signs and symptoms of leukemia include:
- Bone pain or tenderness
- Excessive sweating, especially at night
- Tiny red spots in your skin (petechiae)
- Recurrent nosebleeds
- Easy bleeding or bruising
- Swollen lymph nodes, enlarged liver or spleen
- Losing weight without trying
- Frequent or severe infections
- Persistent fatigue, weakness
- Fever or chills
You should visit your doctor if you have any persistent signs and symptoms that worry you. The symptoms of leukemia are often vague and they are not specific. You may overlook the early leukemia symptoms, because they look like the symptoms of the flu and other common illnesses. There are rare cases when leukemia can be discovered during blood tests for some other condition.
Scientists do not know the exact cause for leukemia. It seems that it is happening as a combination of environmental and genetic factors. Leukemia is happening when the DNA in the blood cells called leukocytes mutate or change, which is disabling the ability to control the growth and division. There are some cases when these mutated cells escape from the immune system and they grow out of control which is crowding out healthy cells in the bloodstream.
There are some factors which can increase the risk of leukemia:
- Family history of leukemia: If some family member has been diagnosed with leukemia, then your risk of this disease can be increased. 
- Smoking: There are some studies in which are shown that smoking can increase your risk of acute myelogenous leukemia. [3,4]
- Exposure to certain chemicals: The exposure to certain chemicals, such as benzene that is found gasoline and it is used in the chemical industry, is linked to an increased risk of some kinds of leukemia. [5,6]
- Genetic disorders: It has been shown that genetic abnormalities are playing role in the development of the leukemia. There are some genetic disorders, such as Down syndrome, are associated with an increased risk of leukemia. 
- Previous cancer treatment: Those people who have had certain types of chemotherapy and radiation therapy for other cancers have an increased risk of developing certain types of leukemia.
But, it is noticed that most people with known risk factors do not get leukemia. And many people, who are diagnosed with leukemia, do not have any of the mentioned risk factors.
The major types of leukemia are:
- ALL (acute lymphocytic leukemia): It is the most common type of leukemia in young children, but also it can happen in adults. 
- AML (acute myelogenous leukemia): This is a very common type of leukemia and it happens in children and adults. It is noticed that it is the most common type of leukemia in adults. 
- CLL (chronic lymphocytic leukemia): When someone has CLL, which is the most common adult leukemia, you may feel well for years without needing a treatment. 
- CML (chronic myelogenous leukemia): This is a type of leukemia which most commonly affects adults. The person who is affected by CML may have few or no symptoms for months or years before they enter a phase in which the leukemia cells grow more quickly. 
- Other types: There are other, rare types of leukemia, including myeloproliferative disorders, myelodysplastic syndromes and hairy cell leukemia.
 Albrecht TA. Physiologic and psychological symptoms experienced by adults with acute leukemia: An integrative literature review. Oncology Nursing Forum. 2014;41(3):286–95.
 Ripert M, Menegaux F, Perel Y, et al. Familial history of cancer and childhood acute leukemia: a French population-based case-control study. European Journal of Cancer Prevention. 2007;16(5):466–70.
 Qin L, Deng HY, Chen SJ, Wei W. Relationship between cigarette smoking and risk of chronic myeloid leukaemia: a meta-analysis of epidemiological studies. Hematology. 2017;22(4):193-200.
 Ugai T, Matsuo K, Sawada N, et al. Smoking and subsequent risk of leukemia in Japan: The Japan Public Health Center-based prospective study. Journal of Epidemiology. 2017;27(7):305–10.
 Snyder R. Leukemia and benzene. International Journal of Environmental Research and Public Health. 2012;9(8):2875–93.
 Poynter JN, Richardson M, Roesler M, et al. Chemical exposures and risk of acute myeloid leukemia and myelodysplastic syndromes in a population-based study. International Journal of Cancer. 2017;140(1):23–33.
 Kumar C. Genetic abnormalities and challenges in the treatment of acute myeloid leukemia. Genes & Cancer. 2011;2(2):95–107.
 Payandeh M, Sadeghi E, Khodarahmi R, Sadeghi M. Appearance and disappearance of chronic myeloid leukemia (CML) in patient with chronic lymphocytic leukemia (CLL). International Journal of Hematology-Oncology and Stem Cell Research. 2014;8(4):49–53.