Side effects of cancer treatment

Treatment side effects vary depending on the type of cancer you have, the stage of the cancer, and the type of treatment you are given. The changes can be both physical and emotional. Some side effects resolve quickly; others can take weeks, months or even years to improve.

Your body will cope with the treatment and recovery in its own way. Try not to compare yourself to others. You should talk to your doctor or nurse about possible side effects before your treatment begins. It is important to know what to watch out for or report, and who to contact out of hours if you have immediate concerns.

On this page you will find details about the following common side effects:

For more information on the specific side effects of each cancer treatment please refer to the Understanding Cancer Treatment booklet series.


Feeling tired and lacking energy (fatigue) is the most common and often the most debilitating side effect of cancer treatment. Fatigue can include feeling exhausted, drowsy, confused or impatient. You may have a heavy feeling in your limbs, get worn out quickly, or find it difficult to do daily activities.

Fatigue can appear suddenly and rest may not relieve it. You might still feel tired for weeks or months after a treatment cycle ends.

Tips for managing fatigue:

  • Ask for help. Get a friend to help with school pick-ups, shopping or running errands.
  • Plan activities for the time of day when you tend to feel most energetic.
  • Be realistic.  Don’t expect to be able to instantly do everything you used to do. Your body is still recovering and it will take time for your energy levels to return.
  • Regular light exercise can help reduce fatigue and increase your appetite. Talk to your health care team about suitable activities for you.
  • Try to eat a well balanced diet with plenty of fruit and vegetables.

Hair loss

Many people having chemotherapy and radiation therapy worry about hair loss. Some people lose all their hair quickly, others lose it after several treatments, or others may only lose a little hair or none at all.

When hair loss does occur, it usually starts 2–3 weeks after the first treatment. Before and while your hair is falling out, your scalp may feel hot, itchy, tender or tingly. Some people find that the skin on their head is extra sensitive and they may develop pimples on the scalp. Although losing head hair is most common, you may also lose hair from your eyebrows, eyelashes, arms, legs, chest and pubic region.

Many people find losing their hair very difficult. You may feel your hair is part of your overall image and its loss can make you feel physically unattractive, vulnerable or sad. It’s natural to feel this way. Talking to your medical team may be helpful.

Tips for managing hair loss:

  • Keep your hair and scalp very clean.
  • Use a mild shampoo like baby shampoo.
  • If you want to use lotion on your head, use sorbolene. Check with your nurse before using any other hair or skin care products.
  • Wear a light cotton turban or beanie to bed if you are cold at night, or to collect hair.
  • Use a cotton, polyester or satin pillowcase as nylon can irritate your scalp. If you prefer to leave your head bare, protect it against sunburn and the cold.
  • Wear a wig, hat, scarf or turban, or go bareheaded, whatever feels best to you.

Cancer Council offers a Wig and Turban service for all cancer patients free of charge. Submit an enquiry online or phone 13 11 20 to find out more.

For more information, read our hair loss fact sheet.


Lymphoedema is swelling (oedema) that occurs when lymph fluids build up in the tissue under the skin. This happens because the lymphatic system in not working as it should in that part of the body. It usually occurs in an arm or leg, but can also affect any part of the body. Lymphoedema can be either primary (having an underdeveloped lymphatic system) or secondary.

Secondary lymphoedema results from damage to the lymphatic system, including from cancer or cancer treatment. Sometimes lymph nodes and lymph vessels are removed or damaged during surgery or radiotherapy, which can stop the lymphatic system from working properly. This means that the lymph fluid doesn’t drain as it should and instead builds up in the tissues, causing swelling.

Because lymphoedema is easier to manage and treat in its early stages, it is important to look out for any signs you are developing lymphoedema.

Signs may begin gradually in the affected area and they may come and go. You may have one or more of the following signs;

  • Tightness, heaviness or fullness
  • Aching or tingling feeling
  • Visible swelling
  • Not being able to fully move the affected limb
  • Pitting on the skin (when an indentation or mark remains in the skin after pressure is applied).

Your doctor will look at your medical history and examine the affected area. They will assess the level of swelling and any pitting, thickening or damage to the skin. Many doctors will refer you to a trained lymphoedema practitioner for a full assessment.

For more information on lymphoedema, please refer to the Understanding Lymphoedema factsheet

Appetite changes

You may lose your appetite because of the effects of cancer itself, the treatment, or other side effects, such as feeling sick, not enjoying the smell of food, or feeling upset. This is a common issue for people diagnosed with cancer.

How to manage loss of appetite

  • Eat small meals frequently, e.g. every 2-3 hours.
  • Use a smaller plate – a big full plate of food may put you off eating
  • Eat what you feel like, when you feel like it.
  • Include a variety of food in your diet as this may improve your overall intake.
  • Sip fluids throughout the day, and replace water, tea and coffee with drinks that add energy (kilojoules/calories), such as milk, milkshakes, smoothies or soup.
  • Relax dietary restrictions. During treatment, maintaining your weight or regaining weight you have lost is more important than avoiding full-fat and other high-energy foods.
  • Gentle physical activity can stimulate appetite.
  • Make meals as enjoyable as possible.

For more information on appetite changes, please refer to the Nutrition and Cancer booklet.

Nausea and vomiting

Feeling sick (nausea) and vomiting are often side effects of cancer, its treatment or some medicines. They often occur together, but not always. Some people experience nausea and vomiting a few hours after treatment, while for others it starts 24 hours later.

How to cope with nausea and vomiting:

  • Have a light snack before treatment and wait a few hours before eating again.
  • Eat small meals 5-6 times during the day
  • Snack on dry or bland foods, and choose cold foods or foods at room temperature instead of hot, fried, greasy or spicy foods.
  • Eat and chew slowly and chew your food well.
  • Try food with ginger, e.g. ginger biscuits or ginger beer.
  • Avoid foods that are overly sweet, fatty, fried, spicy or oily, or that have strong smells.
  • Brush teeth regularly to help reduce unpleasant tastes that make you feel nauseated.
  • Don’t eat your favourite food when feeling nauseated to avoid developing a permanent dislike.
  • Take anti-nausea medicines as prescribed
  • Sip small amounts of fluids as often as possible. Try dry ginger ale, cold flat lemonade, soda water, Lucozade or chilled tomato juice.
  • See your doctor if you can’t keep fluids down, or if the vomiting lasts more than 24 hours, as you may become dehydrated.
  • Introduce drinks slowly once the vomiting has stopped, e.g. clear cool drinks, diluted fruit drinks, Bonox/Bovril, clear broth and weak tea.
  • Start eating small amounts of plain foods once vomiting is under control.
  • Introduce milk gradually and in small amounts or have yoghurt which is easily digested.
  • Gradually increase your food intake until your eating returns to what is normal for you.

For more information on managing nausea and vomiting, please refer to the Nutrition and Cancer booklet.

Constipation and diarrhoea

Cancer treatments may cause constipation and/or diarrhoea.

Tips for managing constipation:

  • Drink plenty of fluid, 8-10 glasses a day.
  • Eat foods high in fibre
  • Ask your doctor about using a laxative
  • Exercise every day – check with your doctor about the amount and type of exercise that is right for you
  • If you have had surgery for bowel cancer, speak to your health care team about specific dietary advice.

Tips for managing diarrhoea:

  • Drink plenty of fluids to avoid becoming dehydrated.
  • Choose low-fibre foods
  • Avoid foods that increase bowel activity
  • Try soy milk or lactose-free milk if you develop a temporary intolerance to lactose
  • Don’t eat too many raw fruit and vegetable skins and wholegrain cereals

For more information on managing bowel changes, please refer to the Nutrition and Cancer booklet.

Sexuality, intimacy and fertility

Whether or not we have a partner, we are sexual beings – having cancer does not change that. Cancer can, however, affect your sexuality and your ability to be intimate in both physical and emotional ways.

It’s best to talk about ways to preserve or protect your fertility before cancer treatment begins. Even if you are not sure whether you want to have children (or more children), it’s worthwhile having the discussion with a fertility specialist or counsellor about storing your sperm or eggs early, so you have options in the future.

Adapting to changes to sexuality, intimacy and fertility:

  • Plan sexual activity for the time of day when your pain is lowest. If you are using pain medication, take it shortly before sex so it will have maximum effect.
  • If you have lost your desire for sexual intimacy, talk to your partner about how the treatment has affected this aspect of your relationship.
  • Ask your doctor about having a hormonal assessment to check your hormone levels. Ask your doctor about taking tablets or having injections to help with erections.
  • Be as active as possible. Plan activities for each day such as exercise, spending time with other people, or reading.

For more information view our Sexuality, Intimacy and Cancer or Fertility and Cancer booklet.