Leukaemia is a blood cancer which occurs in the bone marrow. It produces abnormal quantity  of White Blood Cells (WBC) also called Leucocytes. These WBC's are an important part of body's defense system against infection an diseases. WBC's die fighting the infection. There are two forms of Leukaemia.

1. Acute
2. Chronic

Acute Leukaemia occurs suddenly and grows quickly while Chronic Leukaemia gradually grows and develops over years. Acute and Chronic are further subdivided according to which kind of blood cell is affected. Therefore the split divides Leukaemia into Lymphocytic Leukaemia and Myeloid or Mylogenous Leukaemia. Lymphocytic Leukaemia takes place in a type of marrow cell to form Lymphocytes. Myeloid Leukaemia takes place in a type of marrow cell which goes on to form Red Blood Cells. Combining Lymphocytic and Myeloid Leukaemia there are mainly four main categories.

1. Acute Lymphocytic Leukaemia
2. Acute Myeloid Leukaemia
3. Chronic Lymphocytic Leukaemia
4. Chronic Myeloid Leukaemia

Bad Effects

In the beginning no symptoms can be diagnosed until there is a blood test. When symptoms appear it has similarity with flu-like illness. The symptoms are:

1. Weakness and tiredness
2. Fever and sweat
3. Anaemia, patient becomes pale
4. Loss of weight
5. Have pain in the joints and bones
6. Lymph nodes become swollen
7. Excessive bleeding or bruising
8. Have vomiting feeling

Causes

The factors causing Leukaemia are unknown. It's the most common form of cancer across the world and men are more affected than women. Leukaemia like other form of cancers results from changing in DNA. When someone has leukaemia the control for producing blood cell breaks down. The cancer cells accumulate in the bone marrow and prevent other important blood cells to grow.

Acute Leukaemia is developed by:

• Exposure to radiation
• Smoking
• If someone had previous cancer 
• Any disorders in blood that damages the bone marrow
• Exposure to chemicals such as 'Benzene'

Chronic Leukaemia is developed by:

• Exposure to high levels of ionising radiation
• Ageing

Treatment

Though there are no proven methods of prevention or precaution but there are some ways of treatment.

Acute Lymphocytic leukaemia(ALL)

• Chemotheraphy
• Bone Marrow Transplantation
• Radiotheraphy
• Steroid therapy

Acute Myeloid Leukaemia (AML)

• Chemotheraphy
• Bone marrow transplantation
• Radiotheraphy to the head

Chronic Lymphocytic Leukaemia(CLL)

• Radiation therapy
• Chemotheraphy(stem cell transplant is being tested)
• Lymphocyte infusion
• Removal of spleen by surgery

Bone marrow transplants have to be carried out if chemotherapy treatment fails and more powerful drugs are used. Bone marrow is found in the larger bones such as the spine and femur. If high potential chemotherapy is used this damages the bone marrow and has to be replaced. Drugs are given to stimulate the production of cells for rebuilding bone marrow which are then collected and replaced after the treatment. Or else a donor has to be found whose bone marrow is an exact match with the patient. Chronic Leukaemia can also be treated biologically. Drugs are injected through a tube directly into spine or brain to reach the cells.