What is Leukemia

Leukemia is a cancer (a malignancy) of blood cells. When a person has leukemia, his system produces abnormal white blood cells. These cells are responsible for fighting infection. In case of leukemia the cells don't function properly. As a result it becomes hard for body to fight infections, transport oxygen and control bleeding.
There are known several types of leukemia. These are distinguished by the type of abnormal cells the body produces and how quickly it is developed. Usually a big amount of leukemia cells quickly accumulate in the bone marrow and blood bringing such symptoms as easy bruising, tiredness and susceptibility to infections. If it's acute leukemia, it requires immediate and aggressive treatment.
Leukemia composes about 3% of all new cancer cases in the world.
Over time there can be developed a chronic leukemia. There might not be any specific symptoms at first. But if it's left untreated the amount of abnormal cells can be significantly increased and bring the same symptoms as it happens in case of acute leukemia.
Depending on the type of white blood cell that transforms into leukemia cell, the disease can be classified as lymphoid or myeloid. It is necessary to understand the normal behavior of blood cells to differentiate the different types of leukemia. Generally normal blood cells can develop from stem cells that can become many cell types.
Maturing in the bone marrow, myeloid stem cells transform to immature white cells that are known as myeloid blasts. The blasts later mature to develop into platelets, red blood cells or some specific types of white blood cells. The lymphoid blasts later transform into B or T lymphocytes, which are special white blood cells. Lymphoid leukemia develops from lymphoid cells, while myeloid leukemia arises from the cells that produce myeloid cells.
Understanding the type of cell that is involved in leukemia is crucial in selecting the appropriate treatment.