When you might feel sick

Sickness can begin at different points of your cancer treatment. 

Feeling sick does not happen at the same time for everyone. And you might not feel sick every time you have cancer treatment.

Treatment for feeling or being sick depends on the cause of your sickness and when it starts. Let your doctor or nurse know if you are feeling or being sick. Anti sickness medicines can help.

Sickness straight after treatment

Sickness that starts straight away is called acute onset nausea and vomiting. It may start a few minutes or a few hours after chemotherapy or targeted cancer drug treatment. It usually disappears after 24 hours.

Sickness that starts a day after treatment

Sickness that starts more than 24 hours later is called delayed onset nausea and vomiting. It is most common with the drugs:

  • carboplatin

  • cisplatin

  • cyclophosphamide

  • doxorubicin

It is also more likely with high dose chemotherapy. It might last up to a week after you had your chemotherapy.

You can take anti sickness medicines for a few days after chemotherapy to help delayed onset nausea and vomiting. 

Sickness before treatment

Sickness, before you have treatment, is called anticipatory nausea and vomiting. It happens in up to 30 out of 100 people (up to 30%) having cancer drugs. After a few treatments, particularly if their sickness was not controlled well, people start to feel sick and begin vomiting before their next cancer drug treatment.

The reaction is usually caused by something related to the treatment, like the smell of alcohol wipes or the sight of a nurse's uniform. Some people feel sick if they even start to think about their treatment.

Some people are sick as they get to the hospital or when the nurse starts to set up the drip. Your doctor or nurse might give you anti sickness tablets and often another drug such as lorazepam, to take at home before you set off for the hospital for treatment. This medicine may help you relax and feel more able to cope with your treatment.

What can help?

You can try other ways to try and prevent sickness before treatment such as:

  • relaxation or guided imagery exercises or recordings
  • hypnosis
  • behavioural therapies such as cognitive behavioural therapy,
  • systematic desensitisation (SD), this is where you imagine your feared or anxiety producing event in gradual steps while you practice relaxation techniques
  • distracting yourself with reading, video games, audiobooks, podcasts, music or TV

Treatment for sickness

There are different types of medicines that can help. And there are other ways of controlling sickness due to cancer or its treatment.

  • 2016 MASCC and ESMO guideline update for the prevention of chemotherapy- and radiotherapy-induced nausea and vomiting and of nausea and vomiting in advanced cancer patients
    F Rolia and others
    Annals of Oncology, 2016. Volume 27, Supplement 5

  • Anticipatory Nausea and Vomiting
    JA Roscoe and others

    Support Care Cancer, 2011. Volume 19, Issue 10

  • DeVita, Hellman, and Rosenberg's Cancer: Principles & Practice of Oncology (12th edition)

    VT DeVita, SA Rosenberg and TS Lawrence

    Wolters Kluwer, 2023

Last reviewed: 
14 Aug 2023
Next review due: 
14 Aug 2026

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