Leukemia affects blood or bone marrow. If increasing cancerous cells in bone marrow are replacing normal cells it can damage the bone marrow. As a result blood platelets, which help in blood clotting, are affected. This would lead to excessive bleeding in patients suffering from leukemia.

- Symptoms: Patients can complain of tiredness, weakness, loss of appetite and headache. They could also suffer from fever. They may have swelling or bleeding in gums and enlarged liver and spleen.

- Types of Leukemia:

There are four major types of Leukemia:

1. Acute Lymphocytic Leukemia (ALL) Most of the times children are the victims of ALL. It affects adults above 65 years of age. Treatment of ALL can be divided into induction chemotherapy, consolidation therapy and preventive therapy.

Induction chemotherapy is done to destroy leukemic cells in bone marrow. Through Consolidation therapy, remaining cancerous cells present in the body are destroyed. Preventive therapy prevents cancerous cells to spread to the brain and nervous system.

2. Acute Myelogenous Leukemia (AML) AML is more common in adults than in children. In this type of leukemia, drugs are given in combination to reduce the intensity of the disease and prevent it from recurrence.

3. Chronic lymphocytic leukemia (CLL) People above 55 years of age are more prone to CLL. It does not affect children at all.

4. Chronic Myelogenous leukemia (CML) It occurs mainly in adults. CML can be treated through blood stem cell transplant. Here patient’s stem cells are removed, stored and later transplanted into the patients after cancerous cells have been destroyed.

Chemotherapy can be done but it only normalizes the blood count for some time and cannot increase life span. Gleevec is an example of cancer drugs that kills cancerous cells, leaving out healthy cells.

Changes in the DNA that leads to activation of oncogenes or inactivation of tumor suppressor genes causes Leukemia. These changes may occur spontaneously or due to exposure to radiation or carcinogenic substances.

- Risk Factors: People exposed to petrochemicals like benzene, and hair dyes are more prone to get Leukemia.Viruses can also increase the risk of leukemia. In some cases, HIV virus can be linked to ALL.