Managing the Side Effects of Treatment

Some treatments are more likely to cause side effects than others, and not every person will feel the same effects as someone else, even when they have the same treatment. Preventing and managing side effects is extremely important for the success of your treatment. When you feel better, you’re more likely to complete your treatment as planned, which offers a greater chance for a successful outcome.

Tell your medical team when a new side effect begins, even if you consider it trivial. Remember, your medical team can’t help you if they don’t know how you’re feeling, so be open and honest with them. You may find keeping a diary helpful for tracking side effects. In your diary, be as detailed as possible. Write down when it starts and what you are doing at the time. Include where in your body the side effect occurs, how long it lasts, how severe it is and if anything you do makes it better or worse. Take the diary to your appointments to ensure you remember everything you’d like to discuss.

Following are common side effects. Your doctor may prescribe prescription medications or suggest over-the-counter drugs. If you experience sudden side effects or sudden pains, or if the side effects are getting worse and you aren’t getting any relief, don’t wait for your next appointment. Call your medical team so they can help.

Alopecia (hair loss)

Some treatments may cause loss of hair on the head, face and other parts of the body. Radiation therapy may cause hair loss in the area being treated.

Ask your oncologist for a prescription for a wig. Using certain phrasing, such as “cranial (or skull) prosthesis due to alopecia caused by chemotherapy for cancer” may make the wig eligible for insurance coverage. Read more.

Anemia (low red blood cell count)

Anemia is an abnormally low number of red blood cells in the blood. Red blood cells carry oxygen to the body’s tissues. Anemia can cause many symptoms, most often fatigue and weakness, and can be temporary or long lasting. Read more.

Cognitive Dysfunction (“chemo brain”)

People being treated for cancer often refer to “chemo brain” when they can’t think clearly or have trouble remembering details, such as names and dates. It is associated with chemotherapy but can occur in people receiving all types of treatments. Even though it is treatment-related, some people don’t experience it until months or even years after treatment ends.

Use a daily planner to keep track of things. Solve crossword puzzles or number games to help strengthen your mental ability. Record memory and attention problems to determine when you’re most affected. Don’t multitask; instead, focus on one thing at a time. Read more.


When mild, diarrhea is an inconvenience. If left untreated, it can lead to serious problems, such as dehydration, loss of important nutrients, weight loss and fatigue.

Over-the-counter medicines and fiber supplements are available to control diarrhea, but ask your doctor before taking anything. If diarrhea is severe, your doctor may prescribe other medications or choose to stop your cancer treatment temporarily until your diarrhea is controlled. Your doctor may check you for a Clostridium difficile (C. diff) colon infection.

After treatment begins, you may be able to anticipate when you’ll be affected by diarrhea. If so, mark your calendar so that you aren’t planning to be out for a walk or having company when it is most likely to happen. Read more.


Treatment-related fatigue occurs primarily because the body needs extra energy to repair the healthy tissue damaged by cancer treatment. Additionally, other side effects of treatment, such as pain, nausea and vomiting, can cause or worsen fatigue.

Although most people think more rest will help relieve fatigue, increasing activity and performing regular exercise (such as walking or bike riding) are the best ways to combat it. If your fatigue is severe, your doctor may prescribe a drug to improve alertness. Read more.


Fever, which occurs when the body’s temperature is abnormally high, is the body’s response to infection. Fever can develop in a person who is receiving drug therapy. It can be particularly concerning if it occurs when a person’s white blood count is low. If you recently received chemotherapy and develop a fever, call your doctor immediately. If you know a medication you are taking has fever as a side effect or if you know your white blood count is low, check your temperature if you feel warm or unwell.

Your doctor may recommend over-the-counter medications, such as acetaminophen, to treat the fever related to flu-like syndrome. Avoid non-steroidal anti-inflammatory (NSAID) drugs, as well as aspirin, if you have a bleeding disorder. Discuss all of your options with your doctor before treatment begins to know the best way to manage a fever.

Graft-vs-Host Disease

Graft-versus-host disease (GvHD) is a common side effect of allogeneic stem cell transplantations that can occur when white blood cells from your donor (the graft) recognize healthy cells in your body (the host) as foreign and attack them. Call your doctor immediately if you have dryness of the eyes and mouth; tightening, blistering or burning of the skin; jaundice; fever; sudden weight loss; or abdominal pain or bloating.

Nausea and Vomiting

Nausea and vomiting are side effects that can cause severe dehydration and interrupt your treatment plan. Talk to your doctor about lowering your medication doses or adding antiemetics (anti-nausea drugs) to help keep you comfortable.

It is important for you to contact your doctor if you experience any of the following serious symptoms: more than three episodes of vomiting per hour for at least three hours; blood in vomit; vomit resembling coffee grounds; inability to drink more than eight cups of fluid or ice chips in 24 hours or eat solid food for more than two days; weakness or dizziness; or cannot keep your medications down. Read more.


Neutropenia is a low number of neutrophils, a type of white blood cell. Neutrophils play an important role in preventing infection throughout the body, so having an abnormally low number of neutrophils increases the risk of infection. Neutropenia also makes it more difficult for an infection to resolve.

If you experience any of these serious symptoms, contact your doctor immediately: fever (oral temperature over 100.5°F), OR chills OR sweating; flu-like symptoms (body aches, chills, general fatigue) with or without fever; coughing, shortness of breath or painful breathing; abdominal pain; sore throat or mouth sores; redness, pain or swelling on skin; pus or drainage from any open cut or sore; pain or burning with urination; pain or sores around the anus; or vaginal discharge/itching. Read more.

Oral Mucositis (mouth sores)

Mouth sores are small cuts or ulcers that can affect the gums, tongue, roof of the mouth or lips. Mouth sores sometimes begin as mild pain or burning, followed by white patches that may become large, red lesions. Pain may range from mild to severe, making it difficult to talk, eat or swallow. Your doctor may suggest medicated mouth rinse or another pain reliever. Read more.


Diagnostic procedures, treatments and the disease itself may cause different types of pain, including muscle and bone pain. Untreated pain, even if it’s minor, can get out of hand quickly and affect your body’s ability to heal. That is why it’s so important to let your health care team know right away if you are in pain. Although you can’t expect to be entirely free from pain, you can expect them to do everything possible to make sure you’re comfortable. Read more.

Peripheral Neuropathy

Peripheral neuropathy can result from different types of treatment and usually has a burning or electric shock-like feeling. These symptoms may make it difficult to carry out normal activities, such as buttoning clothes, picking up small items or writing. Muscle weakness and balance problems may cause an unsteady gait or difficulty with walking. Your medical team may suggest seeing a physical or occupational therapist. Some people find relief for neuropathy from exercise, acupuncture or massage therapy. Read more.

Skin Reactions

Skin reactions can include redness and irritation (similar to sunburn), skin rash or dry, flaky skin. Although most reactions are mild to moderate and often cause itchiness and discomfort, some can become severe if not treated early. Your doctor may prescribe a mild corticosteroid cream or an antibiotic gel. Severe rashes are usually treated with an oral antibiotic and perhaps an oral corticosteroid. When a rash is severe, the dose of the cancer drug(s) is often reduced or temporarily stopped until it improves. Read more.

Thrombocytopenia (bleeding/bruising/clotting issues)

Some treatments can interfere with the body’s ability to make platelets, which are a type of blood cell. The result is a condition called thrombocytopenia, and it can lead to bleeding and clotting problems as well as easy bruising. Avoid taking Omega 3 supplements, aspirin and other blood thinners while you’re being treated, and talk with your doctor about any other supplements you may be taking.

For more in-depth information on side effects please visit our Treatment Side Effects section.

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