Leukemia is a cancer of the blood. The first organs in which it appears are the lypmh and the bone marrow, but it can quickly spread in the whole body through the blood. Leukemia occurs when the organs mentioned above start to produce too many white blood cells, saturating the body with them. Furthermore, the white blood cells are defective and they can't protect the body from infections like they are supposed to, so a person suffering from leukemia is very sensitive to bacteria and viruses.

Leukemia is a very complex disease, which has many forms and which is also hard to treat. The treatment depends on what type of leukemia the patient has. There are two main types of leukemia, acute leukemia and chronic leukemia.

Chronic leukemia is leukemia that is still in an early phase. Not all the white blood cells are abnormal, some can still protect the body against infections, and it can be treated with a higher chance of success. Unfortunately, in many cases chronic leukemia presents no symptoms so it's harder to detect it.

Acute leukemia is an advanced form of the cancer. There are no more normal white blood cells in a person with acute leukemia. Moreover, the number of defective blood cells keeps increasing. Acute leukemia advances very quickly.

The doctors also divide the blood cancer into two more categories, depending on what type of blood cells are affected. There are myeloid blood cells and lymphoid blood cells. When the lymphoid blood cells are affected the illness is called lymphocytic leukemia and when the myeloid ones are abnormal it's called myelogenous leukemia.

Therefore if we combine the four types we get:

-chronic lymphocytic leukemia - it affects people over 60 years of age usually and it is treated with chemotherapy

-acute lymphocytic leukemia - affects many children, usually under 6 years old. It spreads very quickly and it is treated with chemotherapy, but the survival rate is lower.

-chronic myelogenous leukemia - this form affects middle aged people, and the treatment is successful in most cases. It is treated with imatinib mesylate and chemotherapy.

-acute myeloid (myelogenous) leukemia - affects adults and it's also treated with chemotherapy. The younger the patient is the higher the survival chance.

It is important to determine what type of leukemia a patient has, because the treatments vary. For more information on this topic and to find out more about the treatment that corresponds to each leukemia type you should consult your local doctor.