15 Major Side Effects of Chemotherapy

Once cancer is diagnosed, the first step most doctors recommend is enrolling in chemotherapy. While it’s widely recognized as one of the most effective cancer treatments, not many people realize that chemotherapy, alongside its benefits, can also cause significant harm to the body.

Chemotherapy involves a combination of powerful drugs designed to target and destroy rapidly dividing cancer cells. Unfortunately, these drugs don’t distinguish between cancerous and healthy cells, often damaging healthy ones in the process.

This can result in a wide range of side effects, which vary in intensity from person to person. Factors such as age, overall health, and the specific type of chemotherapy being administered influence how severe these side effects might be.

While most side effects typically fade after treatment concludes, some may linger for an extended period, and a few might persist long-term, proving difficult to overcome.

No matter what symptoms you’re experiencing, it’s crucial to keep your doctor informed. By understanding the side effects you're facing, your doctor can consider adjusting the dosage or switching to a different chemotherapy approach.

# Cutaneous Toxicity

Approximately 60–80% of chemotherapy patients experience cutaneous toxicity. These effects can be dose-dependent and include skin dryness, paronychia, rashes, itching (pruritus), mucositis, and hair-related changes.

# Hepatotoxicity

Certain chemotherapy drugs can severely affect liver function. These toxic substances may accumulate faster than the liver can process them, leading to potential liver damage.

# Alopecia (Hair Loss)

Hair loss is one of the most distressing side effects of chemotherapy. For many patients, the fear of going bald is so overwhelming that it leads them to consider avoiding treatment altogether. The sudden loss of hair can be emotionally devastating and deeply impact self-esteem.

# Thrombocytopenia

Chemotherapy can lead to a reduced platelet count (thrombocytopenia), which can impair the blood’s ability to clot. If platelet levels drop below 30,000, the risk of prolonged bleeding increases significantly.

# Ocular Toxicity

In some cases, chemotherapy may harm the optic nerves. Common complications include dry eyes, glaucoma, and retinal damage, which can affect vision.

# Gastrointestinal Side Effects

Nausea, vomiting, diarrhea, and constipation are frequently experienced during chemotherapy. While often manageable, these symptoms can sometimes become severe—such as in cases of bloody stools or persistent soft stool.

# Hemorrhagic Cystitis

This condition may develop during or after chemotherapy. Symptoms can include lower abdominal pain, painful urination, frequent urination, urgency, and blood in the urine.

# Mucositis (Mouth Sores)

A common side effect of both chemotherapy and radiation, mucositis causes painful mouth sores. It varies in severity and can significantly impact eating and overall nutrition.

# Anemia

Chemotherapy can damage red blood cells, leading to anemia. This condition is marked by fatigue and sluggishness, and affects around 70% of chemotherapy patients.

# Cognitive Impairment (Chemo Brain)

Patients may notice memory lapses and difficulty concentrating during or after chemotherapy. Though often temporary, these cognitive changes can be frustrating and long-lasting.

# Nephrotoxicity

Some chemotherapy agents can harm kidney function by affecting renal tubules, glomeruli, and other kidney structures. An increase in serum creatinine levels may indicate the onset of kidney damage, which in turn can alter drug metabolism and cause further toxicity.

# Cardiotoxicity

Chemotherapy may cause heart damage (cardiotoxicity), either early on or later in treatment. While some effects may be mild, such as changes in blood pressure, more severe reactions can lead to heart failure.

# Fatigue

Extreme tiredness is a common and often intense side effect of chemotherapy. Factors like anemia, emotional stress, other treatments, and disrupted sleep contribute to this overwhelming fatigue.

# Fertility Issues

Certain chemotherapy treatments can affect fertility in both men and women. Women may experience temporary or permanent infertility, while in men, chemotherapy can lower sperm count or even result in total sperm damage. Pregnancy during chemotherapy is strongly discouraged.

# Sexual Dysfunction

Chemotherapy can lower sexual desire in both men and women. This loss of libido is a significant side effect that can impact relationships and emotional well-being.