Leukemia, also known as multiple myeloma is the cancer of the blood. Cells of the blood, mainly white blood cells (also called leukocytes) affected by cancer are known as blood cancer cells. Any normal blood cell (erythrocytes, leukocytes and blood platelets) originates in the bone marrow. The cells of the bone marrow are called stem cells. Stem cells develop into three different types of cells on maturing depending on the nature of the tasks they perform. Red blood cells carry oxygen for the body, blood platelets help in blood clots which controls bleeds and white blood cells help fight infection. Blood cancer cells are cells of the blood (basically white blood cells) which forget to die after completing their life cycle. As a result there exists an excess of white blood cells.

The blood cancer cells eat away the resources of the otherwise non-infected cells rendering them unfit for proper functioning of their tasks. As the white blood cells mainly fight diseases, a person suffering from blood cancer loses his/her immunity against various infections. Thus diarrhea, pneumonia, fever and other flu like signs are common symptoms of blood cancer.

Other symptoms include weakness, the feeling of fullness, bone and joint pain, pain in the lower back, swelling and pain in the stomach. Since the oxygen supply to the body is also through the blood, breathlessness is another symptom caused by the non-functioning blood cancer cells. Anemia, anorexia and sudden weight loss are also caused by infected blood cancer cells. Anemia and breathlessness are both caused by the low red blood cell (which contains hemoglobin that is the oxygen carrier) count in the body.

Unlike other cancers, there exists no tumor in leukemia. The blood cancer cells in the bone marrow undergo uncontrolled proliferation as a result of which the entire bloodstream has blood cancer cells. Thus leukemia can be mostly diagnosed with a blood smear test. The blood cancer cells i.e. the white blood cells, when observed under a microscope will appear to be unusually large in number. The red blood cells (erythrocytes) on the other hand will be extremely small in number in a leukemia patient. Other diagnostic tests include lymph node biopsy and bone marrow biopsy. The treatment for this disease involves bone marrow transplant. Blood cancer is basically cancer of the bone marrow and replacing the infected bone marrow so as to stop the supply of blood cancer cells to the body is an apt treatment.