Treatment Side Effects

Side effects occur when healthy cells are damaged. Different chemotherapy and radiation treatments cause different side effects. Side effects may happen right away, a week to 10 days later, or even months to years later.

In general, the side effects from chemotherapy depend on the type and dosage. Side effects of radiation depend on which part of the body is treated. For example, if the hips receive radiation, only the skin, bone marrow, and hipbone may be affected. Your health care provider will talk with you about the side effects that your child may experience.

Appetite Problems

Both cancer and its treatment can cause appetite problems. Fear, worry, and stress also can decrease the desire to eat. On the other hand, some children may be hungry, but may feel full, reducing their food intake. Regardless of the cause, appetite problems can result in poor weight gain or weight loss if they persist.


Constipation occurs when a child has hard stools (bowel movements) that occur less frequently than usual. Some types of chemotherapy, such as vincristine, and pain medications can cause constipation. 


Fever, vomiting, and diarrhea can cause dehydration, especially if your child cannot drink enough to replace the fluid that is lost.


If your child has diarrhea tell your health care provider the color, amount and number of times in a day that it occurred. 


Many children with cancer experience fatigue during and following treatment. Children may describe fatigue as being tired and/or feeling weak. 


While a fever may be a sign of a serious infection in anyone, in a child with cancer, it can be quite serious. Left untreated, your child could become very ill. If your child has a fever, call your health care provider right away. Do not wait until your medical facility opens. Call (309) 624-4945

Hair Loss (Alopecia)

Some kinds of chemotherapy and radiation therapy to the head may cause hair loss or thinning of the hair. Hair loss may start 7 to 10 days after the first treatment. In some cases, all of the hair falls out, including eye lashes, eye brows, underarm hair, etc.

Low Platelet Count (Thrombocytopenia)

Platelets stop bleeding in the body by forming clots. When the platelet count is low, your child may be at risk for bleeding. A normal platelet count is between 150,000 and 300,000.

Low Red Blood Cell Count (Anemia)

Red blood cells carry oxygen throughout the body. Oxygen enters the lungs with each breath and binds (attaches) to hemoglobin in the red blood cells. Hemoglobin carries the oxygen to all the organs and tissues in the body. Two laboratory tests are done to measure the number and function of red blood cells.

Low White Blood Cell Count (Neutropenia)

White blood cells fight infection. A normal white blood cell count is between 5,000 and 10,000 cells. A white blood cell count below 1,000 cells increases the risk of infection. In some cases, your child may be given a medicine, such as “G-CSF (granulocyte-colony stimulating factor),” to help increase the number of white blood cells in the bone marrow.

Mouth Sores and Dry Mouth

Cells in the mouth can be affected by chemotherapy and radiation therapy to the head and neck. As such, it’s important to keep the mouth and teeth as clean as possible. Your child will feel more comfortable, and you can help prevent mouth sores or other infections.

Nausea and Vomiting

Chemotherapy and radiation therapy can cause nausea, vomiting and diarrhea. Any of these symptoms can place your child at risk for dehydration (loss of fluids in the body).


There are many causes of pain in children with cancer. Cancer cells in the blood or solid tumors in the body can cause bone or tissue pain. Some side effects of cancer treatment, such as mouth or skin sores, can be painful. Tests, like bone marrow aspirates and lumbar punctures, can be painful.

It is important to tell your health care team if your child has pain, so they can determine the cause and work with you to create a plan to decrease the pain as much as possible.

Skin Changes

Skin changes are also common and are called radiation dermatitis. Treat the skin that is exposed to radiation with extra care. The skin in the area receiving treatment may become red and sensitive, similar to sunburn. Radiation can also cause hair loss in the area being treated. 

Weight gain from steroids

Steroids (such as prednisone or dexamethasone) may cause your child to gain excess weight. Steroids can cause an increase in appetite and a build up (retention) of fluid. 

Weight loss

Many children lose weight during chemotherapy or radiation treatments. Your health care team will closely watch your child’s weight.