What is leukemia?
What is leukemia?
Leukemia is a malignancy (cancer) of blood cells. Leukemia involves the production of abnormal white blood cells — the cells responsible for fighting infection. However, the abnormal cells in leukemia do not function in the same way as normal white blood cells. The leukemia cells continue to grow and divide, eventually crowding out the normal blood cells. The end result is that it becomes difficult for the body to fight infections, control bleeding, and transport oxygen.
Common types of leukemia
There are different types of leukemia, based upon how quickly the disease develops and the type of abnormal cells produced. Leukemia is called an acute leukemia if it develops rapidly. Large numbers of leukemia cells accumulate very quickly in the blood and bone marrow, leading to symptoms such as tiredness, easy bruising, and susceptibility to infections. Acute leukemia requires fast and aggressive treatment.
Chronic leukemias develop slowly over time. These leukemias may not cause specific symptoms at the beginning of their course. If left untreated, the cells may eventually grow to high numbers, as in acute leukemias causing similar symptoms
- Acute lymphocytic leukemia (ALL, also known as acute lymphoblastic leukemia) is the most common type of leukemia in children, but it can also affect adults. In this type of leukemia, immature lymphoid cells grow rapidly in the blood.
- Acute myeloid leukemia (AML, also called acute myelogenous leukemia) involves the rapid growth of myeloid cells. It occurs in both adults and children
- Chronic lymphocytic leukemia (CLL) is a slow-growing cancer of lymphoid cells that usually affects people over 55 years of age. It almost never occurs in children or adolescents.
- Chronic myeloid leukemia (CML, also known as chronic myelogenous leukemia) primarily affects adults.
What causes leukemia?
For most cancers, researchers are still trying to understand how they are caused. The same is true for leukemia – doctors do not know what causes it. Medical researchers have identified certain risk factors that make leukemia more likely.
- Exposure to radiation is known to increase the risk of developing AML, CML, or ALL.
- Exposure to benzene, used commonly in the chemical industry, increases the risk of leukemia.
- Cigarette smoking is known to increase the risk of developing AML.
- Down syndrome, Li-Fraumeni syndrome, and other medical conditions can increase the risk of developing leukemia.
- Blood disorders known as myelodysplastic syndromes confer an increased risk of developing AML. Human T-cell leukemia virus type 1 (HTLV-1) is a virus that causes a rare type of leukemia.
What are leukemia symptoms and signs?
The symptoms and signs of leukemia depend upon the type of leukemia. As stated earlier, slow-growing or chronic leukemia may not cause any symptoms at the outset, while aggressive or rapidly growing leukemia may lead to severe symptoms.
- Night sweats
- Swollen lymph nodes that are usually painless
- Feelings of fatigue tiredness
- Easy bleeding or bruising, causing bluish or purplish patches on the skin or tiny red spots on the skin, or recurring nosebleeds.
- Frequent infections
- Bone or joint pain
- Weight loss that is otherwise unexplained, or loss of appetite
- Enlargement of the spleen or liver, which can lead to abdominal pain or swelling
- Red spots on the skin
- Skin nodules