Chemotherapy, frequently abbreviated as "chemo," is a type of cancer treatment that employs one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) in a standard regimen. Chemotherapy may be administered with the intention of achieving a cure, which almost always involves the use of combinations of drugs, or it may be employed with the aim of prolonging life or reducing symptoms, a process known as palliative chemotherapy. Chemotherapy is one of the principal areas of medical practice devoted to the pharmacological treatment of cancer, which is referred to as medical oncology. The term chemotherapy now encompasses the nonspecific use of intracellular poisons to inhibit mitosis (cell division) or to induce DNA damage (thereby enabling DNA repair to augment chemotherapy). This definition excludes the more selective agents that block extracellular signals (signal transduction). Therapies that target specific molecular or genetic pathways, inhibiting growth-promoting signals from classic endocrine hormones (primarily estrogens for breast cancer and androgens for prostate cancer), are now referred to as hormonal therapies. Other inhibitions of growth signals, such as those associated with receptor tyrosine kinases, are classified as targeted therapy.
Drugs (like chemo, hormone therapy, or targeted therapy) are used to treat cancer in a way that affects the whole body. They enter the bloodstream and can target cancer cells anywhere in the body. This type of therapy is often used with other local treatments, such as radiation, surgery, and hyperthermia.
The way traditional chemotherapeutic agents work is by interfering with cell division (mitosis), but cancer cells vary a lot in how susceptible they are to these agents. In essence, chemotherapy is a way of damaging or stressing cells, which may then lead to cell death if apoptosis is initiated. A lot of the side effects of chemotherapy can be traced back to damage to normal cells that divide quickly and are therefore sensitive to anti-mitotic drugs. These include cells in the bone marrow, digestive tract and hair follicles. This is why you often see side effects like myelosuppression (which means there are fewer blood cells, so the immune system is also affected), mucositis (inflammation of the digestive tract lining) and alopecia (hair loss). Because they affect immune cells (especially lymphocytes), chemotherapy drugs are often used to treat diseases that result from the immune system attacking the body's own tissues (autoimmunity). These include rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, vasculitis and many others.
What is Chemotherapy Side Effects?
Very Common Side Effects (Often Occur):
Hair Loss (Alopecia): This is one of the most well-known side effects. Chemotherapy targets hair follicles, causing hair to thin or fall out entirely. Hair loss can occur on the scalp, as well as other parts of the body like eyebrows, eyelashes, and body hair. Hair usually grows back after treatment ends, although the texture or color may be temporarily different.
Nausea and Vomiting: Chemotherapy can irritate the stomach and trigger the brain's vomiting center. Anti-nausea medications (antiemetics) are routinely prescribed to prevent or manage this side effect.
Fatigue: This is a very common and often debilitating side effect. It's not just feeling tired; it's a profound sense of exhaustion that doesn't improve with rest. Fatigue can be caused by various factors, including anemia, changes in metabolism, and the body's response to treatment.
Mouth Sores (Mucositis): Chemotherapy can damage the cells lining the mouth, leading to painful sores, ulcers, and inflammation. Good oral hygiene is essential to minimize this side effect. Special mouthwashes and pain relief medications can be used for treatment.
Changes in Blood Counts (Myelosuppression): Chemotherapy affects the bone marrow, where blood cells are produced. This can lead to:
Neutropenia (Low White Blood Cell Count): Increases the risk of infection.
Anemia (Low Red Blood Cell Count): Causes fatigue, weakness, and shortness of breath.
Thrombocytopenia (Low Platelet Count): Increases the risk of bleeding and bruising.
Loss of Appetite (Anorexia): Nausea, mouth sores, and changes in taste can contribute to loss of appetite.
Changes in Taste and Smell: Chemotherapy can temporarily alter taste buds and the sense of smell, making food taste different or unpleasant.
Diarrhea or Constipation: Chemotherapy can affect the digestive system, causing either diarrhea or constipation.
Less Common Side Effects (May Occur):
Peripheral Neuropathy: Damage to the nerves, often causing numbness, tingling, pain, or weakness in the hands and feet.
Skin and Nail Changes: Skin may become dry, itchy, or develop rashes. Nails may become brittle, discolored, or develop ridges.
Cognitive Changes (Chemo Brain): Some people experience problems with memory, concentration, and thinking clearly. These changes are usually temporary.
Fluid Retention (Edema): Swelling in the hands, feet, ankles, or legs.
Heart Problems (Cardiotoxicity): Some chemotherapy drugs can damage the heart muscle. This is more common with certain drugs and higher doses.
Lung Problems (Pulmonary Toxicity): Some drugs can damage the lungs, leading to shortness of breath or cough.
Kidney Problems (Nephrotoxicity): Some drugs can affect kidney function.
Fertility Problems: Chemotherapy can affect fertility in both men and women. It's important to discuss fertility preservation options with your doctor before starting treatment.
Secondary Cancers: In rare cases, chemotherapy can increase the risk of developing a second cancer years later.
Managing Chemotherapy Side Effects:
Many strategies and medications are available to manage chemotherapy side effects:
Medications: Anti-nausea drugs, pain relievers, growth factors to stimulate blood cell production, and other medications can help alleviate symptoms.
Lifestyle Changes: Getting enough rest, eating a healthy diet, staying hydrated, and engaging in light exercise can help manage fatigue and improve overall well-being.
Complementary Therapies: Techniques like acupuncture, massage, and relaxation exercises may help reduce some side effects.
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