How to explain cancer to your child

Use your understanding of your children’s individual personalities and needs to guide what information you share and how you share it.

Oncology (cancer) team members such as social workers, play therapists, nurses, doctors & psychologists are available to help you explain things to your child.

Some parents like to tell their children by themselves at the hospital. Others prefer to wait until they go home or may ask the doctor or social worker to be present and help explain the situation to the child. You can ask the medical team for support from the social work unit. 

Explaining cancer and treatment

To help your child understand cancer, first talk about how healthy bodies work:

  • cells are the building blocks of our bodies
  • every part of the body is made of cells (hair, bones, blood, heart, skin, etc)
  • in healthy bodies, cells work together to help our body do things like killing germs or giving us energy. 

After explaining how the healthy body works, talk with your child about cancer.

  • avoid using 'bad cells' and 'good cells' when talking about cancer so your child does not think they have 'bad cells' because they are a 'bad kid'
  • use words like 'sick cells' and 'healthy cells'.

After explaining what cancer is, talk with your child about cancer treatments (see below for more details). Explain that they may receive more than one type of treatment and that other children may receive different types of treatment too. 


  • Leukaemia is a cancer of the blood
  • bone marrow is a factory where our blood is made deep inside our bones
  • it makes red blood cells (which carry oxygen and nutrients through the body)
  • it white blood cells (which fight germs and infections) and platelets (which help stop bleeding
  • Leukaemia cells are sick blood cells that do not work properly and take over healthy blood cells.

Lymphoma and Hodgkin's disease

  • the body has a defence system, the immune system
  • the immune system finds cells that are not healthy or cells that do not belong in the body and destroys them
  • lymphoma and Hodgkin's disease are cancers of the immune system 
  • the sick cells do not work properly to protect the body and take over the healthy cells in the immune system.

Solid tumours

  • explain the job of the area of the body where the cancer is located. (For example, talk about how leg bones support your body and help you walk)
  • a solid tumour is a lump of sick cells stuck together
  • these sick cells are more than the healthy cells and keep them from doing their job.


  • chemotherapy is also often called chemo
  • it is medicine that gets rid of cells that are growing too quickly
  • cancer cells grow very fast, Chemotherapy is given to get rid of cancer cells
  • our bodies also have healthy cells that grow fast
  • chemotherapy can hurt the healthy cells 
  • when chemotherapy attacks healthy cells, children may have side effects such as hair loss, upset stomach, mouth ulcers, fever. tiredness, or infection.
  • not all children have all of these side effects, it will depend on the body's response  and type of treatment. 


  • radiation uses strong x-rays that you cannot see or feel
  • machines focus these rays on the area of the body where the cancer is located
  • it destroys sick cells to stop them from growing or spreading 
  • radiation can also hurt healthy cells that are close to where the cancer is, but they get better 
  • when radiotherapy hurts healthy cells, children may have side effects such as hair loss, upset stomach, mouth ulcers, fever. tiredness, or red skin
  • not all children have all of these side effects, it will depend on the body's response and type of treatment.


  • surgery is when a special doctor takes out all or part of your tumour
  • during surgery you are given a special medicine (anaesthesia) that allows you to be in a deep sleep so you cannot feel or see anything
  • the doctor will wake you up when the surgery is all finished. 

Emotions and feelings

After explaining cancer and treatment to your child, talk to them about their feelings. 

  • assure them that their feelings are normal 
  • they may feel angry, sad, lonely, scared, confused 
  • be honest with your child about your feelings, they can sense if you're not okay
  • your child may hold back or feel scared if you do not share your feelings with them 
  • sharing your feelings lets them know that it's okay to feel the emotions they are experiencing.
Last updated Sunday 5th November 2023