Side Effects

Treating cancer may cause side effects, but many ways to manage them are now available. Preventing and managing side effects is extremely important for the success of your treatment because the better you feel, the more likely you’ll be able to complete your treatment as planned. Your doctor can help you anticipate the most common side effects, so that you are prepared if they occur.


One of the most common side effects of cancer and its treatment is pain. For many people, pain is related to the cancer itself. But cancer treatments, such as surgery, can sometimes cause pain as well. Chemotherapy and radiation therapy can cause pain by damaging healthy cells, which can result in side effects such as a burning sensation, mouth sores, diarrhea, nerve damage and more. You should not avoid these treatments because they may cause pain. Rather, you should talk to your doctor openly about any pain you experience so it can be controlled.

The options for managing cancer pain are numerous, and it can be helpful to think of them as tools in a toolbox. Sometimes just one tool can fix the problem, but at other times, you may need a combination of tools. In addition, you’ll sometimes need to use tools in a particular sequence, and other times you may need to switch back and forth between tools.

The following descriptions of various pain relief techniques provide a general overview of what’s available. If your doctor doesn’t mention one or more of them for your care, don’t be afraid to ask whether they might be right for you.

  • Pharmacotherapy is the treatment of cancer pain with medications, including non-opioid drugs, opioids (narcotics), adjuvant drugs (drugs not typically used for pain but that may be helpful for managing pain) and topical analgesics.
  • Percutaneous pain techniques are procedures that enable access to inner organs and tissues through needle punctures into the skin. These procedures include ablative techniques (radiofrequency ablation or cryotherapy), nerve blocks, kyphoplasty, vertebroplasty and sacroplasty.
  • Neurosurgical approaches to pain relief seek to lessen pain at its source by interrupting pain signals between the spine and brain.
  • Intrathecal drug delivery, also called a “pain pump,” sends pain medication directly to your spinal cord using a small pump that’s surgically placed in the abdominal wall.
  • Supportive oncology usually involves a team of doctors who can help relieve cancer pain through palliative surgery, radiation therapy and chemotherapy.
  • Physiatry, or physical medicine and rehabilitation, helps relieve pain through customized therapy programs designed to enhance mobility, overcome disabilities and avoid painful activities when cancer or its treatments have affected how you move and function. Anti-inflammatory injections also are a part of this technique.
  • Complementary strategies include yoga, acupuncture, reflexology, massage therapy, aromatherapy, art therapy, music therapy and animal therapy. These strategies do not single-handedly resolve cancer pain, but they can often help contribute to managing pain.
  • Psychobehavioral strategies involve activities such as deep relaxation and meditation. They are useful in calming psychologic symptoms, such as anxiety and depression, which often accompany cancer pain and can get in the way of its treatment.

All of the types of pain relief are associated with certain risks and benefits, so always review them with your health care team before beginning any type of regimen.


People who receive abdominal radiation therapy or take certain chemotherapy or targeted therapy drugs are the most likely to experience diarrhea. Cancer treatment-related diarrhea is a short-term side effect, and dietary changes can help prevent or lessen diarrhea. Once diarrhea occurs, following a diet of only clear liquids may help the lining of your intestines heal. Clear liquids include water, cranberry juice, ginger ale, clear broth, popsicles, decaffeinated tea and gelatin. As diarrhea begins to improve, you can slowly add solid foods back into your diet, starting with low-fiber foods, such as white rice and boiled potatoes.

In addition, over-the-counter medicines and fiber supplements are available to control diarrhea, but be sure to talk to your doctor before taking any of them, as he or she may give you instructions that differ from those on the drug label. If your diarrhea is severe, your doctor also may prescribe other medications or temporarily stop treatment with chemotherapy or targeted therapy and restart it when your diarrhea is controlled.


Regardless of the type of cancer you have or the type of treatment you receive, almost everyone treated for cancer experiences fatigue at some point. Cancer treatments contribute to fatigue primarily because the body needs extra energy to repair the healthy tissues damaged during treatment. In addition, other treatment side effects (such as pain, nausea and vomiting) can cause or worsen fatigue, and certain medications you may take to relieve those side effects can lead to fatigue as well — as can the interaction of two or more medications.

Managing fatigue largely depends on the cause. For example, if your doctor determines that a certain drug or drug interaction is causing your fatigue, you may need to change or stop taking those drugs or supplements. However, if the cause is unclear, you may need to try something more general, such as increasing your activity level. Although most people think more rest will help relieve fatigue, the opposite is actually true. Participating in regular exercise (such as walking or riding a bike) is the best way to help manage and reduce symptoms of fatigue.

If your fatigue is severe, your doctor may prescribe something to help improve your alertness and raise your energy during the day, while also decreasing fatigue. Managing fatigue is an essential part of your health care, so be sure to discuss with your doctor.

Hair loss (alopecia)

Hair loss, also called alopecia, occurs most commonly among people receiving chemotherapy and/or radiation therapy. Some targeted therapy drugs also may cause hair loss. Typically, chemotherapy drugs cause hair loss on the head and body, whereas radiation therapy causes hair loss only in the area being treated. However, not all people treated for cancer will lose their hair even when they take the same drug or have the same treatment.

It’s difficult to prevent hair loss caused by chemotherapy. However, being gentle with your hair may help reduce the severity of your hair loss and improve the regrowth of your hair. Here are some suggestions you might try. Be gentle with your hair by using a soft brush or wide-toothed comb. Do not use hair dye or heating devices, such as dryers, rollers and curling irons. Sleep on a satin or silk pillowcase. Avoid braids and ponytails, which can cause breakage. Use a gentle pH-balanced shampoo.

Nausea and vomiting

Prevention is the key to managing nausea and vomiting, as these symptoms are easier to prevent than to control once they’ve started. If your treatment plan includes chemotherapy, radiation therapy or both, nausea and vomiting are potential side effects. Certain targeted therapy drugs also may cause nausea and vomiting. Antiemetics are drugs that can help prevent and control nausea and vomiting. Some antiemetics are best for mild nausea and vomiting, and others are appropriate for more severe symptoms.

Vomiting can be prevented with the appropriate medications, but some people may still have nausea without vomiting. Medications to prevent vomiting should be taken as prescribed before treatment. And they should be continued after treatment as directed by your doctor because the risk of vomiting may continue for several days after treatment.

It’s important to let your doctor know if you’re still experiencing nausea and vomiting even after taking an antiemetic as prescribed. This type of nausea and vomiting is known as “breakthrough,” and you many need a different antiemetic drug or a higher dose in order to control these symptoms.


Neutropenia is most likely to occur in people receiving a combination of radiation therapy and chemotherapy, but it’s also common in those who receive either of these two treatments alone. Neutropenia is a low number of neutrophils, a kind of white blood cell that helps fight off infection. Therefore, neutropenia increases the risk of infection. Neutropenia cannot be prevented, so it’s important to take steps to reduce your risk for infection. Studies have shown that the most effective way to prevent infection is frequent hand washing.

Your doctor will closely monitor your white blood cell count throughout your treatment period. If your neutrophil count is extremely low, your doctor may delay your next treatment until it has increased. In the meantime, he or she likely will have you follow “neutropenic precautions,” which are extra measures to prevent infection:

  • Taking your temperature four times each day
  • Not eating uncooked foods
  • Staying away from fresh flowers, plants and gardening
  • Avoiding enemas, rectal suppositories and rectal thermometers
  • Delaying dental work

Certain growth factors may help people with an extremely low neutrophil count. These growth factors are special proteins that can stimulate the bone marrow to produce more white blood cells, and they’re usually given as an injection under the skin (subcutaneously). The growth factors used most often to treat neutropenia are filgrastim (Neupogen) and pegfilgrastim (Neulasta).

In patients who have a high risk for infection, prophylactic (preventive) antibiotics or antifungal medications may be used as well. If an infection develops, antibiotics are usually administered immediately because cancer-related infections are considered emergencies.

Skin reactions

Skin reactions are likely for people who receive chemotherapy, radiation therapy and targeted therapy. Chemotherapy destroys rapidly dividing cancer cells, but it also may damage normal cells in your body that divide rapidly, including blood cells and cells in your mouth, nails, hair and skin.

Radiation absorbed by the skin during radiation therapy also may trigger skin reactions, but they usually are minor and do not require treatment. Targeted therapy drugs may cause skin reactions by blocking specific molecules in cancer cells. Because these molecules also are important for the normal growth of skin cells, blocking them can lead to skin reactions. Reactions caused by targeted therapy drugs, however, can range from mild to severe. If a rash develops and spreads over a larger area and causes itchiness or pain, your doctor may prescribe a mild corticosteroid cream (hydrocortisone) or an antibiotic gel (clindamycin gel). Severe rashes are usually treated with an oral antibiotic and perhaps an oral corticosteroid, such as methylprednisolone (Medrol) or prednisone (Rayos).

The acne-like rashes caused by targeted therapy drugs also can be treated with topical and oral antibiotics and corticosteroids. If your rash is severe, your doctor may reduce the dose of the targeted therapy drug or temporarily stop treatment, restarting it if the rash gets better within two weeks.

Additional Resources


Previous Next


Register Now! Sign Up For Our Free E-Newletter!

Read Inspiring Cancer Survivor Stories

Order Your Guides Here