Leukemia or leukaemia is a type of cancer of the blood or bone marrow and characterized by an abnormal growth of white blood cells. Leukemia usually begins in the bone marrow, which is the soft tissue found in the interior of bones.

Symptoms are difficult to spot and can be easily confused with other diseases. Confirmation must be done only after medical tests are made.

Classification of Leukemia:

-         Acute Leukemia. It appears as result of a fast progressing accumulation of immature cells in the blood and bone marrow.

-         Chronic Leukemia. It appears slowly and allows more mature cells to be formed.

-         Lymphocytic Leukemia. It occurs in the marrow that produces lymphocytes

-         Myelogenous Leukemia. It develops from abnormal myeloid cells.

Types are mixed and often shortly described as AML (Acute Myelogenous Leukemia), ALL (Acute Lymphocytic Leukemia), CML (Chronic Myelogenous Leukemia), and CLL (Chronic Lymphocytic Leukemia)

The causes of leukemia are unknown but there are certain risk factors that increase the chance that this type of cancer may develop. These include:

-         Exposure to large amounts of different types of radiations.

-         Exposure to harmful chemical compounds.

-         The presence of certain types of virus (like the HIV).

-         Family history (genetic cause).

-         Chromosomal abnormalities (like Down syndrome).

Several procedures can help to confirm the disease:

-         Physical Examination.

-         Blood tests, including complete blood account, blood film, and cytogenic analysis.

-         Biopsy of the bone marrow and/or lymph node.

-         Lumbar puncture (spinal tap).

-         Ultrasounds.

-         X-ray.

-         CT scan.

-         MRI scan.