How A Child Understands Cancer

Approved by the Cancer.Net Editorial Board, 09/2019

For most parents, few things are as frightening as hearing from the doctor that your child has cancer. Parents are dealing with their own fears and confusion at this time. Yet, they must also face the task of helping their child understand his or her diagnosis.

Whether to tell your child that he or she has cancer

Many parents think they can protect their child by not telling him or her about the cancer. But it is important to name your child’s medical condition as “cancer.” Parents should also further describe it since your child will hear this language from others. For example, call it by the type of cancer, such as sarcoma, leukemia, or a brain tumor.

Naming a child’s illness as cancer is important. It helps build trust with your child, helps him or her feel included in medical exchanges, and decreases confusion. Also, it prevents your child from learning that he or she has cancer by hearing it from someone else. Your child is also more likely to cooperate with the tests and treatments.

Children who do not know about their cancer use their thoughts to fill in the knowledge gaps. For example, they may think their illness is a punishment for doing something wrong. Or that they did something bad to make themselves sick. Furthermore, not knowing what is wrong or what to expect may cause your child anxiety, stress, and fear. Most children already know that something is wrong. They may not be feeling well or may wonder about frequent visits to the doctor or hospital.

What to tell your child

What you tell your child will depend on his or her age. It should also be based on what you think he or she is able to understand. The following information briefly describes what children of different ages are likely to understand:

Ages 0 to 3

  • Cannot understand cancer

  • Are most afraid that the medical staff will take them away from their parents

  • Are most afraid of medical tests they cannot understand

  • Need you to assure them that you will not abandon them at the hospital

  • Have no way of knowing what it means to have a procedure or take a trip to the hospital far in advance. Yet, parents should tell them about upcoming events in simple, clear, and reassuring language.

  • Preschoolers may have fears that they will live in the hospital forever. Tell your child that when treatment is finished, he or she can return home (if that is true). If you know how many more days your child will be in the hospital, share these details.

Ages 3 to 7

  • Understand cancer explained in simple terms

  • Look for a specific cause for the cancer, such as something they did or thought

  • Need assurance that they did not cause the cancer

  • Need assurance that you will not abandon them

  • Are afraid of pain. Be honest with your child about tests and treatments that may hurt. Also, explain that they are having the treatment to help make them better. You may also explain that doctors can help make treatments less painful.

  • Preschool-aged children may fear that they will end up living at the hospital. It is important to let your child know he or she can return home (see above).

Ages 7 to 12

  • Can understand a more detailed explanation of cancer

  • Are less likely to believe that their cancer occurred because they did something wrong

  • Are more likely to understand that they will need to take medicine and have other treatments to get better

  • Are afraid of pain, so be honest with them about likely pain from tests and treatments

  • Will hear messages about cancer from other sources, such as school, TV, and the Internet. Try to encourage your child to share any details he or she learns with you. It will help if you can discuss it together, instead of having your child worry alone.


  • Can understand a complex explanation of the cancer and may have many detailed questions. They may be interested in learning more about their diagnosis.

  • Are most likely to think about the cancer in terms of its symptoms and effect on daily life, such as school, sports, and friends.

  • Will likely hear messages about cancer from many sources. Do your best to ask about any details your teen is getting elsewhere. Also, learn about your teen’s specific fears so that you can discuss it together and/or with the health care team.

  • Understand the relationship between their symptoms and cancer and the role of treatment

  • May want to play a role in making decisions about their treatment

  • Often have a unique set of concerns about their physical appearance and their need to fit in with others. They may worry about losing their hair and large weight changes. Talk honestly with your teen about the possible side effects.

Tips for talking with your child about his or her cancer

  • Practice what you are going to say before you talk with your child. Ask for advice from your child's health care team or another parent who has been in a similar position.

  • When you first talk with your child, consider asking another person to be with you. This might be another family member who can provide support. It could also be a doctor or nurse who can help describe cancer in detail.

  • A single conversation with your child will not be enough. Have frequent, brief conversations with your child to keep the lines of communication open.

  • Be open and honest and encourage your child to ask questions. Answer questions honestly, even if this means you do not know the answer and need to follow up later.

  • Share your feelings with your child and encourage them to share too. You are your child's most important source of info and support. If they think they cannot share their feelings with you, they may think they cannot share them with anyone. Then they may feel completely alone.

  • Your child may hear words related to cancer at the doctor’s office or hospital. Explain the meaning of these words in a way they can understand. For example, chemotherapy is "special drugs to get rid of the cancer." A tumor is "a lump inside your body." Learn more about basic cancer terms.

  • Talk with your child about the treatments they will need and what will happen during each treatment. Be honest about the possibilities of pain and other side effects. Learn more about preparing your child for medical procedures.

  • Seek support for yourself, your child, and your family. Sources of support include hospital social workers, support groups, individual and family counseling, and religious or spiritual resources.

A special note on talking with your child about death

Some parents face the challenge of helping their child prepare for death. Each family has its own beliefs about death. How and when you talk with your child about death and dying is a personal decision. Children also need to know that they will not be alone and that the health care team will help manage pain and other symptoms. Read more about caring for a terminally ill child.

Related Resources

Guide to Childhood Cancer

How to Talk to Your Preschooler About Cancer

More Information

National Cancer Institute: Children with Cancer - A Guide for Parents