Chemotherapy side effects and how to manage them

This page was reviewed under our medical and editorial policy by

Swapnil Rajurkar, MD, Medical Oncologist and Hematologist, City of Hope | Duarte

This page was reviewed on June 1, 2023.

When a patient's cancer care team recommends chemotherapy during cancer treatment, it may spark concerns because chemotherapy (also referred to as chemo) has potential side effects—some mild and some severe, some short-term and some long-lasting.

Not everyone experiences every side effect. Some people may have just a few. Some may have many side effects, but none severe. Others may experience debilitating side effects and serious, long-term complications such as heart or nerve damage.

The patient's cancer care team will be careful to prescribe the right amount of chemotherapy to be effective while keeping side effects to a minimum. Patients may undergo more than one chemotherapy treatment.

Why does chemotherapy cause side effects?

Chemotherapy drugs are designed to kill fast-growing cancer cells. However, as these powerful drugs travel throughout the body, they also destroy normal, healthy cells, which may cause side effects.

The normal cells that chemotherapy drugs are most likely to damage are:

  • Hair follicles
  • Cells that form blood, found in bone marrow
  • Cells in the digestive tract, starting in the mouth
  • Cells in the reproductive system

How long do side effects from chemotherapy last?

Patients may find that some side effects come and go surprisingly quickly. But it may take months to completely get over other side effects. Some side effects subside between treatments and some, especially serious ones, may be lifelong.

Common reactions such as nausea or vomiting and fatigue may start as soon as the first treatment. Others, such as a second cancer, may not appear for many months or years.

Don’t get discouraged. Patients and their cancer treatment teams work together to prevent and reduce side effects of chemotherapy.

Common side effects of chemotherapy

Knowing as much as possible about the different side effects and what to expect may put patients more in control and at ease.


A feeling of utter exhaustion, or fatigue, is the most common side effect of chemotherapy. Scientists don’t fully understand why chemotherapy causes extra fatigue in cancer patients, but they suspect it’s the body’s response to having to work harder to rid itself of the toxic substances left behind. Chemotherapy also may wreak havoc on sleep patterns, making it hard for patients to get the healing rest they need.

Many patients seem to experience the most chemo-induced fatigue midway through their treatments. Fatigue seems to decrease when treatments stop, but it may take months after the last treatment until patients feel like themselves again.

To help manage fatigue:

  • Get regular exercise. This may sound counterintuitive, but even light activity for a short period of time may help combat fatigue. Choose an enjoyable exercise and slowly increase the amount of time performing it. A good goal: three to five hours of moderate activity (like walking) each week. Performing exercises such as yoga and tai chi, and combining movement (stretching, balancing, controlled breathing) with activities like meditation may help reduce fatigue.
  • Establish a routine. Make a schedule for each day, including the activities that are important. Patients may have more energy in the morning after sleeping, or after lunch. Plan activities that require the most energy for those times.
  • Adopt healthy sleep habits. Establishing a nighttime routine may help patients sleep better. Naps are OK, as long as they don’t last more than an hour. Keep the bedroom quiet and dark—and avoid distractions such as noise and the TV.
  • Work with the care team. Make sure the care team is aware of any instances of fatigue. They may help look for other factors that may be contributing to it such as anemia, depression or troublesome pain.

Hair loss (alopecia)

Some chemotherapy drugs may cause the patient's hair to thin, and others cause it to fall out. Patients may lose the hair not only on their heads, including eyebrows and eyelashes, but also on their arms, legs and pubic area.

Some ways to manage hair loss:

  • Be proactive. Patients may consider cutting their hair short or shaving their heads before their hair starts to fall out.
  • Consider a head covering. Some people buy wigs or wear scarves. Ask the health care team to help determine whether a wig would be covered by insurance. The American Cancer Society has a program, Tender Loving Care, that helps provide wigs, hats and scarves.
  • Be gentle. Patients may not lose as much hair if they're extra-kind to their heads—don’t brush too often or pull too hard or use blow dryers and curling irons. Avoid perms and dyes, especially when the hair starts to grow back.
  • Consider a cold cap. Some patients find that cooling caps help reduce hair loss. These devices deliver cold temperatures to the scalp area, constricting the blood vessels so the chemotherapy drugs provide less of an impact to the hair follicles. Some patients find that cooling caps reduce their risk of hair loss, but others find them to be uncomfortable and cause headaches.

Nausea and vomiting

Certain drugs are more likely to cause nausea and vomiting than others, including those that target cancers of the gastrointestinal tract, liver and brain.

These factors also may increase your risk of nausea and vomiting:

  • Gender (females are more at risk)
  • Age (Younger patients tend to experience worse symptoms)
  • A history of morning sickness and motion sickness during pregnancy
  • History of prior chemotherapy treatments
  • Tendency to be prone to vomiting when sick

Patients may start feeling nauseated and vomit within the first 24 hours of treatment, especially if it’s administered through an intravenous (IV) infusion. That’s because drugs given intravenously are absorbed faster. Patients also may experience nausea and vomiting as many as a few days after their latest treatment.

Anticipating treatment or the smells may make some people nauseous and vomit as well.

Tips for managing nausea and vomiting include:

  • Pre-treat. Ask the care team for anti-nausea medicines, specifically those shown to work best for each type of treatment. Start them before the first session and continue taking them until treatment is complete. Ginger may be helpful when used along with other anti-nausea treatments or for certain chemotherapy regimens.
  • Practice relaxation techniques. Meditation, breathing exercises and progressive muscle relaxation (tensing and relaxing muscles) have been shown to reduce nausea and vomiting.
  • Avoid having an empty stomach. An empty stomach may cause patients to feel nauseated. Eat small meals and snacks throughout the day. Sipping clear liquids (cold, not hot) such as ginger ale, tea and broth may help. Suck on ice chips or chips made from freezing juice. Go for bland food such as toast and crackers.

Constipation and diarrhea

Treatment may cause dietary changes (patients aren't drinking as much or eating as much fiber) and activity levels (patients aren't moving or exercising as much). These lifestyle changes may also affect bowel habits.

To reduce constipation:

  • Drink lots of fluids. Aim for eight, 8-ounce glasses of fluid each day (exceptions apply for patients with kidney or heart disease).
  • Eat more fiber. Fruits and vegetables and whole grain breads and cereals are great sources. Be sure to drink more fluids when eating a high-fiber diet constipation doesn't get worse.
  • Get moving. The more patients move, the better it is for their abdominal muscles. If walking isn't an option, ask about abdominal exercises that are safe to do in a bed or chair.

Check with the care team before taking laxatives for constipation. Using them too often may cause further constipation. Suppositories or enemas may cause bleeding or infections or other side effects in some cancer patients.

Chemotherapy also may cause diarrhea any time during treatment. How to manage this side effect:

  • Keep diet in mind. Eat frequently—but small amounts each time. Avoid milk and other dairy products, spicy and fatty foods, nuts, seeds and coconut. Don’t drink alcohol, caffeinated drinks (tea, coffee, hot chocolate) or carbonated beverages.
  • Add probiotics. Natural yogurt is an excellent source of probiotics, which are live microorganisms that help digestion.
  • Drink liquids. Be sure to replenish fluids to avoid dehydration. Stick to clear liquids such as chicken broth and ginger ale.
  • Ask the care team before taking medicines for diarrhea. They may be able to prescribe the medicine that’s best for the patient and his or her drug regimen.

Changes in appetite

Patients may lose their appetites from nausea and vomiting or from painful mouth sores. They also may lose the desire for food because of all they're going through.

To manage:

  • Eat small amounts. Try sampling small amounts five or six times a day rather than three big meals. Go for foods and drinks that are loaded with protein and calories.
  • Eat by the clock. Make a schedule and eat when the clock says it’s time, not just when hunger hits. Patients may not feel hungry when they’re receiving chemotherapy.
  • Get moving. Patients may increase their appetites by being active. Consider a short walk before lunch or dinner, or some stretches between meal times.

Mouth sores

Chemotherapy may harm the cells in the mouth, throat and lips because they too are fast-growing. This may cause sores to develop, making it hard to eat.

To manage the sores:

  • Maintain mouth moisture. Have a glass of water nearby and take small sips throughout the day. Consider sucking on ice chips, popsicles and/or sugar-free hard candy or chewing sugar-free gum.
  • Eat foods that are soft, moist and easy to swallow, such as oatmeal, mashed potatoes and scrambled eggs. Puree foods or soften them with gravy and sauces.
  • Try a mouth rinse. Avoid mouthwash that has alcohol in it. Prepare this rinse instead: a quarter-teaspoon baking soda, 1/8 teaspoon salt and 1 cup warm water. Use the rinse three or four times a day.


Many cancer patients want to know whether chemotherapy is painful, and in some cases, it may be. Chemotherapy pain may come in many different forms, such as headaches, stomachaches or muscle pain. Patients may experience pain, burning and numbness, especially in the hands and feet, from the cancer as well as the chemotherapy. Pain control is important, and there are many treatments to help patients feel better.

To manage:

  • Take pain medicine. Ask the care team about prescribing pain medicine, which may be helpful when taken on a set schedule or as needed.
  • See a pain specialist. Patients may request a meeting with a pain or palliative care expert and discuss ways to control pain.
  • Learn to relax. Many patients find that relaxation techniques such as deep breathing or yoga may help reduce muscle pain and tension.

Second cancers

Some chemotherapy drugs have been linked to a number of different second cancers. The risk of this side effect increases the longer treatment lasts and the higher the dose intensity.

The most likely second cancers from chemotherapy are blood cell cancers: myelodysplastic syndrome (MDS) and acute myelogenous leukemia (AML). Patients may develop one or both. MDS may occur first and then become AML.

Speak with a health care team about the risk for developing a second cancer from chemotherapy treatment.

Other possible side effects of chemotherapy

Depending on the cancer and chemotherapy treatment, patients also may experience some of these side effects:

When to seek medical attention for side effects

While some chemotherapy side effects are minor and likely to subside, others may be alarming and long-lasting. Alert the cancer care team immediately if any of the following occur:

  • High fever (100.5 to 101 degrees Fahrenheit)
  • Chills that won’t stop
  • Bleeding or unexplained bruising
  • Allergic reaction that causes severe itching or trouble swallowing or breathing
  • Intense headaches or other unusual pain
  • Blood in urine or stool
  • Difficulty urinating
  • Persistent diarrhea or vomiting

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