Chemotherapy is a treatment that uses drugs to kill fast growing cells in your body.
Cells are the basic units that make up the human body. Cells grow and divide to make new cells as the body needs them. Usually, cells are replaced by new cells when they die or get damaged. Cancer begins when these cells start to grow abnormally, which may also lead to the formation of a mass called a tumor. Cancer such as leukemia, some types of lymphoma, and myeloma do not form a tumor.
Chemotherapy is most often used to treat cancer. Chemotherapy drugs interfere with a cancer cell's ability to divide and reproduce. There are different drugs available for different phases in the cell life cycle, and these drugs can be used alone or in combination. Chemotherapy can be used as a sole treatment, or it can be used after other treatments to kill any cancer cells that might remain in the body, which is called as adjuvant therapy. Chemotherapy can also be used for neo-adjuvant therapy, which involves using it to shrink tumors so that other treatments, such as radiation and surgery, are possible. Chemotherapy may help relieve signs and symptoms of cancer by killing the cancer cells, which is called palliative therapy. Some chemotherapy drugs have proved useful in treating other conditions too, such as bone marrow diseases and immune system disorders. [1,2]
Chemotherapy is an invasive treatment that can have severe adverse effects, both during the therapy and even sometimes after. The reason behind this is that it cannot differentiate between healthy and cancer cells, so, it tends to target both.
Common side effects of chemotherapy drugs include:
• Diarrhea - Chemotherapy can lead to diarrhea, as the body expels damaged cells. These symptoms often begin few days after the treatment starts.
• Hair loss - Chemotherapy drugs attack fast-growing cells, such as hair cells. This may cause some people to experience hair loss.
• Loss of appetite - Chemotherapy can affect how the body processes nutrients, which leads to a loss of appetite and weight loss.
• Fatigue - the most frequent side effects of chemotherapy.
• Mouth sores
• Constipation - Chemotherapy can lead to constipation, as the body expels damaged cells.
• Easy bruising - Chemotherapy can reduce a person's platelet count, which means the blood will not clot as effectively. This leads to easy bruising.
• Bleeding - more bleeding than usual from a small cut; Chemotherapy can also cause frequent nose bleeds or bleeding gum.
• Anemia – 70% of people undergoing chemotherapy develop anemia, as it causes RBC levels to fall.
• Mental health problems - Chemotherapy can lead to difficulty with reasoning, organizing, and multitasking. Some people experience depression.
• Hearing impairment- Toxins in some chemotherapies can affect the nervous system, leading to temporary or permanent hearing loss.
Most of these side effects can be treated or prevented, as many of them subside after treatment ends. However, since these side effects can be severe, it may be best to avoid pregnancy while having treatment. [1,2]
That being said, chemotherapy can also cause side effects long after the treatment. These side effects vary depending upon the chemotherapy drugs, but can include:
• Kidney problems
• Damage to lung tissues
• Heart problems
• Infertility- Some types of chemotherapy can reduce a person's fertility.
• Nerve damage
• Risk of second cancer - Chemotherapy has been linked to a small increase in risk for blood cancers.
• Nervous and muscular systems damage - The central nervous system controls emotions, thought patterns, and coordination. Chemotherapy drugs may cause problems with memory or make it difficult to concentrate or think clearly. This is also called “chemo brain.”
• Loss of bone mass - It's common to lose bone mass with age, but some chemo drugs can increase this loss. [1,2]
These lists beg the question: Why should anyone take this treatment?
Chemotherapy is still a mainstay of most cancer treatments. It has saved millions of lives, and for most cancer patients, it's still the best option. It’s important to remember that each person's situation is different. Individuals with certain types of cancer who receive early chemotherapy treatment may achieve a complete cure. This makes the side effects worthwhile for many.
Before starting the treatment, a person should be aware of why they are recommended chemotherapy and if there are other options. Honest, open conversations regarding outcome potentials and expectations with friends, family, and healthcare professionals are very important. The cost of the treatment can also be an issue for many people, so they must contact the insurance provider about covering the cost before starting the treatment. 
Since chemotherapy and the reality of having and battling cancer can be emotionally trying, some individuals may find it helpful to talk with a counselor about the mental and emotional aspects of cancer and chemotherapy.
1) MediLexicon International. (n.d.). Chemotherapy: What it is, what to expect, side effects, and outlook. Medical News Today. https://www.medicalnewstoday.com/articles/158401.
2) Mayo Foundation for Medical Education and Research. (2020, March 5). Chemotherapy. Mayo Clinic. https://www.mayoclinic.org/tests-procedures/chemotherapy/about/pac-20385033.
3) MediLexicon International. (n.d.). The 10 most common chemotherapy side effects. Medical News Today. https://www.medicalnewstoday.com/articles/323485
Author: Sanket Ahire
Editor: Lauryn Agron
Health scientist: Sanket Ahire