Chemotherapy is the use of chemical agents to treat or control diseases. It works by killing fast dividing cells like cancerous cells and other healthy cells which include hair follicles, bone marrow, reproductive system etc. You would get anxious at the mention of chemotherapy for above reasons but there is not much cause for worry as healthy cells regenerate fast after the therapy is complete. Chemotherapy is either used exclusively or in combination with radiation or surgical therapies. Advantages Unlike radiation, which kills cancer cells in the target area, chemotherapy is universal and treats the entire body. This attacks the untreated cancer cells from the previous cancer too. Doctors use chemotherapy depending on the spread and type of cancer to ·Destroy cancer cells from the body, no withstanding its wide spread ·Prolong life expectancy by controlling cancer growth and spread ·Alleviate symptoms and improve quality of life Chemotherapy Types and Methodology Chemotherapy is not always based on a single drug for the fear of developing resistance to the drug. On the other hand a combination has different actions at the cellular level and kills more cancer cells preventing further spread. Your doctor decides on the combination considering your age, tolerance limit, and health. Mind you, all such combinations are tested on patients with similar conditions. A few representative types. 1.Alkylating agents, deter the replication of DNA, prevents cancer cell growth. 2.Antimetabolites, block the enzyme supply to cancer cells on which they thrive. 3.Anti-tumor antibiotics change cell membranes by blocking enzyme supply led cell division. These are not the general antibiotics. 4.Nitrosoureas obstruct the ways DNA is repaired by enzymes. 5.Mitotic inhibitors inhibit cell division by hindering enzymes essential in the cell reproduction. Chemotherapy is administered cyclically considering the type of drugs and your condition. Chemotherapy drugs travel thru the entire body, so there are four ways devised for administration. 1.Intravenous method where drug is injected into your veins. 2.Oral chemotherapeutic pills to swallow. 3.Topical application (ointments) for skin cancers. 4.Intramuscular injection. Side Effects On the lighter side there are side effects like vomiting, nausea, hair loss, dry mouth, constipation and loss of appetite etc. Beware, some problems like damages to heart, lungs and kidneys show much after the treatment. Urinating blood and nervous damage and attack of secondary cancers like lymphoma, leukemia is not ruled out.