As medical science progresses, treatments for diseases once thought untreatable have emerged. One disease that can now often be treated is leukemia. Leukemia is a cancer of the blood. It affects the body's ability to fight infection, heal itself and function normally.

There are four major types of leukemia, and several subtypes within each category. The main types are acute and chronic lymphocytic leukemia, and acute and chronic myeloid leukemia. As a rule, the acute types progress quickly, while the chronic leukemias progress more slowly. Chronic lymphocytic and acute myeloid are the most common kinds of leukemia, while acute lymphocytic is the most common in children.

In lymphocytic leukemia, the bone marrow produces too many lymphoblasts. A lymphoblast is an immature white blood cell formed from a lymphoid stem cell. In myeloid leukemia, too many immature white blood cells are present. These white blood cells are formed from myeloid stem cells, which also form red blood cells and platelets.

Leukemia may be caused by a genetic defect, or it may be a result of exposure to high levels of radiation or certain chemicals. It may also be caused by medications used to treat other types of cancer. Persons with Down Syndrome are also at a higher risk for leukemia.

Regardless of the type of leukemia a person may have, the symptoms are often similar. Symptoms may include fevers or night sweats, frequent infections, a weak or tired feeling, headache, bleeding and bruising easily, pain in the bones or joints, abdominal swelling or discomfort, swollen lymph nodes and weight loss. None of these are diagnostic per se, but taken together, they often point to leukemia as a cause. Diagnosis is made through a biopsy of the bone marrow, which indicates the abnormal cells.

Once the physician has a positive diagnosis of leukemia, he or she will often refer the patient to an oncologist who specializes in treating leukemia. The specialist will probably consult with other doctors in the field about the patient, and they will begin to assemble a treatment plan. Treatment will depend on the kind of leukemia the patient has. With early stage chronic lymphocytic leukemia, a patient may not require immediate treatment, but instead, may be tested for signs of the disease's progression. Although chronic lymphocytic leukemia can rarely be cured, patients can achieve and maintain mostly symptom-free remission.

Chemotherapy, radiation therapy, immunotherapy and bone marrow transplants are the main weapons in the arsenal to treat leukemia. The immediate goal of treatment is to bring a patient into a symptom-free remission. The long-term goal is to keep the patient in remission. Patients may receive one or a combination of these treatments to achieve a cure. Many patients with acute leukemia can be cured, so immediate treatment should always be considered.

Hospitals like St. Jude's Children's Research Hospital in Memphis, Tennessee have been at the forefront of research for treatment and cures for leukemia, and their research has saved an untold number of lives. With the advances in medical science in just the past 15 years or so, leukemia is no longer the death sentence it once was. Patients now have hope for a cure.