Consent to treatment is the principle that a person must give permission before they receive any type of medical treatment, test or examination. This must be done on the basis of an explanation by a clinician.

Consent from a patient is needed regardless of the procedure  whether it's a physical examination, organ donation or something else. The principle of consent is an important part of medical ethics and the international human rights law.

This topic covers:

Defining consent

How consent is given

Consent from children and young people

When consent isn't needed

Consent and life-sustaining treatment


Defining consent

For consent to be valid, it must be voluntary and informed, and the person consenting must have the capacity to make the decision. These terms are explained below:

  • Voluntary  the decision to either consent or not to consent to treatment must be made by the person themselves, and must not be influenced by pressure from medical staff, friends or family.
  • Informed  the person must be given all of the information in terms of what the treatment involves, including the benefits and risks, whether there are reasonable alternative treatments and what will happen if treatment doesn't go ahead.
  • Capacity  the person must be capable of giving consent, which means they understand the information given to them, and they can use it to make an informed decision.


If a person doesn't have the capacity to make a decision about their treatment, the healthcare professionals treating them can go ahead and give treatment if they believe it's in the person’s best interests.

However, the clinicians must take reasonable steps to seek advice from the patient’s friends or relatives before making these decisions.

Read more about assessing the capacity to consent.

How consent is given

Consent can be given:

  • verbally  for example, by saying they're happy to have an X-ray
  • in writing  for example, by signing a consent form for surgery

Someone could also give non-verbal consent, as long as they understand the treatment or examination about to take place for example, holding out an arm for a blood test.

Consent should be given to the healthcare professional directly responsible for the person's current treatment, such as:

  • a nurse arranging a blood test
  • a GP prescribing new medication
  • a surgeon planning an operation

If someone is going to have a major medical procedure, such as an operation, their consent should ideally be secured well in advance, so they have plenty of time to obtain information about the procedure and ask questions.

If they change their mind at any point before the procedure, the person is entitled to withdraw their previous consent.

Consent from children and young people



Read more about the rules of consent applying to children and young people

When consent isn't needed


It may not be necessary to obtain consent if a person:

  • requires emergency treatment to save their life, but they're incapacitated (for example, they're unconscious)  the reasons why treatment was necessary should be fully explained once they've recovered
  • immediately requires an additional emergency procedure during an operation  there has to be a clear medical reason why it would be unsafe to wait to obtain consent, and it can't be simply for convenience
  • with a severe mental health condition – such as schizophrenia, bipolar disorder or dementia – lacks the capacity to consent to the treatment of their mental health (under the Mental Health Act 1983)  in these cases, treatment for unrelated physical conditions still requires consent, which the patient may be able to provide, despite their mental illness
  • requires hospital treatment for a severe mental health condition, but self-harmed or attempted suicide while competent and is refusing treatment (under the Mental Health Act 1983 the person's nearest relative or an approved social worker must make an application for the person to be forcibly kept in hospital, and two doctors must assess the person's condition
  • is a risk to public health (due to rabies, cholera or tuberculosis (TB)
  • is severely ill and living in unhygienic conditions (under the National Assistance Act 1948 a person who is severely ill or infirm and is living in unsanitary conditions can be taken to a place of care without their consent

Consent and life-sustaining treatments

A person may be being kept alive with supportive treatments  such as lung ventilation  without having made an advance decision, which outlines the care they would refuse to receive.


To help reach a decision, the healthcare professionals responsible for the person’s care should discuss the issue with the relatives and friends of the person receiving the treatment.

They should consider, among other things:

  • how long the person may live if treatment is continued
  • whether there's any chance of the person recovering

Treatment can be withdrawn if there's an agreement that continuing treatment isn't in the person's best interests. The case will be referred to the courts before further action is taken if:

  • an agreement can't be reached

It's important to note the difference between withdrawing a person's life support and taking a deliberate action to make them die. For example, injecting a lethal drug would illegal.


If you believe you've received treatment you didn't consent to, you can make an official complaint.

Read more about how to make a complaint.

Page last reviewed: 03/03/2016

Next review due: 01/03/2019