• Posted February 15, 2026

Why Chemo Causes Unwanted Side Effects And How To Treat Them

Chemotherapy is one of the most common weapons in the cancer-treatment arsenal, but its side effects are well known.

Hair loss. Nausea and vomiting. Mouth sores. Fatigue.

The side effects a person with cancer may have are affected by the type of cancer being treated and the chemotherapy drug being used. But a Boston-based cancer specialist told NIH News in Health that there are ways to manage many of them.

"Chemotherapy does work," said Dr. Ting Bao, a cancer specialist at the Dana-Farber Cancer Institute in Boston. "There are side effects, but they are becoming more and more manageable."

Chemo uses drugs to kill cancer cells or stop their growth. 

Side effects emerge when normal body cells are caught in the crossfire. As NIH explains, your body needs new cells to replace old or damaged ones. Some cells multiply fast, such as those lining the intestines or those involved in hair growth. Chemo drugs can kill these cells, too.

Chemo can also lower the number of white blood cells available to fight off disease, putting patients at increased risk of infection. Some chemo drugs also cause neuropathy that leads to pain, tingling, numbness and balance problems.

As researchers explore new ways to reduce chemo’s side effects, some tools in the present-day arsenal include:

• Anti-nausea drugs to help with nausea and vomiting

• Dietary changes to manage nausea, fatigue and mouth sores

• Exercise and good sleep habits to fight fatigue

• Medication to address some kinds of chemo-related pain

Based on a patient’s symptoms, doctors can recommend which strategies might help most. 

Meanwhile, researchers are looking for new ways to reduce chemo-related side effects. 

Some are investigating whether herbal remedies, like ginger, may help with nausea, the NIH said. Bao is investigating whether acupuncture and yoga may help treat the chemo-induced neuropathy.

"These ancient modalities intrigue me because they don’t have much side effects," she told News in Health. "For acupuncture, the most common side effects are a little bruising and bleeding. And for yoga, joint and muscle pain." 

Trials are ongoing, she said. 

Other researchers are trying to understand the underpinnings of chemo-related neuropathy and testing drug treatments.

Patients preparing for chemo should ask their health care team about ways to manage side effects. Here is a list of questions to ask:

• Based on my cancer type or treatment, what side effects am I at risk for?

• When are side effects likely to emerge and how long might they last?

• What can I do to feel better? 

• What medicines, foods and drinks can help? Which should I avoid?

• What safety precautions do you recommend?

• What signs or symptoms should I call you about?

More information

Learn more about the side effects of chemotherapy at the American Cancer Society.

SOURCE: NIH News in Health, February 2026