Blood - it is an integral part of the body, the primary fluid, without which our life is impossible. The defeat of the blood disease affects all organs. This often leads to hematological malignancies - a whole group of neoplastic diseases of the hematopoietic tissue. When cancer cells invade the bone marrow(the place where form and mature blood cells) - a leukemia (leukemia, leukemia). All leukemias are divided into acute and chronic. Acute causes uncontrolled growth of young (immature) blood cells andchronic leukemia blood, lymph nodes, spleen and liver dramatically increases the number of the more mature cells. Acute leukemia occurs much heavier than chronic, and requires immediate treatment.