You are here: HomeEthical IssuesConsent → Legal considerations

Ethical Issues - Consent

Legal considerations

In England and Wales the Mental Capacity Act (2005) sets out the legal position relating to determination of capacity and the principles for treating adults who lack capacity. The Act is applicable to people aged 16 years and older and states that capacity should be assumed unless it is established that he or she lacks capacity. A similar Act (Adults with Incapacity (Scotland) Act 2000) sets out the legal framework in Scotland. There is no statutory legislation governing consent in children under the age of 16 years but there is clear case law to guide practitioners (see below). A further key piece of statutory legislation in relation to consent to treatment is the Mental Health Act (2007) which provides the legal framework for treating adults without their consent in carefully specified circumstances of mental illness.

A comprehensive review of the Mental Capacity Act for clinical ethics committees can be found on this here.

Form of Consent (Express / Implied)

Consent provides lawful justification for treatment. If valid consent is not given, any treatment which involves touching e.g. physical examination, surgery, dressing a wound, would amount to a battery.

There is no legal requirement that consent should be written, or be in a particular form - oral consent is valid (or it may be implied from circumstances, where for example a patient undresses prior to examination). However a written consent form provides evidence of consent and is recommended for major interventions such as surgical procedures. The Department of Health has produced standardized consent forms.

Consent may be withdrawn at any time, even after signing of a consent form, and to proceed with treatment where consent has effectively been withdrawn would constitute a battery.

In order for consent to be valid it must be:

  • given by someone who is competent (has legal capacity)
  • sufficiently informed
  • freely given


Battery is any non-consensual touching - it does not have to harm the patient. A doctor can commit a battery even though the doctor considers he is acting in the best interests of his patient by treating him/her. To avoid liability in battery the patient should be informed in broad terms of the nature of the procedure that is intended to be carried out and give consent to it.

There are very few cases where a doctor has been successfully sued for battery.

Devi v West Midlands RHA [1980] C.L.Y. 687

A woman underwent a hysterectomy to which she did not consent (she had given consent to repair her uterus). The Court found the surgeon liable in battery as there was total lack of consent to the nature of the operation.


If the patient claims that he has not been sufficiently informed about the risks inherent in the treatment and alternatives to the treatment then liability does not lie in battery but rather in negligence. In deciding whether non-disclosure is negligent it is necessary to determine whether there is a responsible body of clinicians in the relevant field who would warn of the relevant risks (the Bolam test). In the area of disclosure of risk, however, the judges are more ready than in other areas of clinical negligence to go against expert medical evidence in deciding what amounts to “responsible” practice.

Past judgments in legal cases have suggested that a patient should be informed of risks if:

  • the incidence of the risk is sufficiently high - for example a 1% risk of stroke
  • if the risk materialised it would have serious consequences for the patient (It is worth noting that identifying serious consequences for the patient requires knowledge of what might be important consequences for the patient)
  • the patient specifically asks about a risk

Chatterton v Gerson [1981] 1 ALL ER 257

Mrs Chatterton suffered intractable pain as a result of a trapped nerve following a hernia operation. Dr Gerson, a pain specialist, performed an operation to relieve the pain, but this resulted in permanent immobility of her right leg. Mrs. Chatterton said that she should have been informed of this risk and claimed in battery.
It was held that she had been informed in broad terms of the nature of the procedure ie. she had been informed and consented to an operation to her right leg. The fact that she may not have been informed of the risks of paralysis to her leg could not amount to battery but any claim would have to be made in negligence.

Capacity to consent to treatment

Capacity is treatment specific - it depends on the treatment to be performed. If the treatment is risky / has potential serious side effects / is complicated, it may require a greater degree of understanding to make a decision than is necessary for treatment that is straightforward or less invasive. Thus a patient can have capacity to consent to one procedure, but not to another. Capacity can also fluctuate.

Tests of capacity

People aged 16 years and over

The Mental Capacity Act sets out the criteria for capacity.
A patient has capacity to consent / refuse medical treatment if he/she can:

  • Understand the information relevant to the decision
  • Retain the information long enough to make a decision
  • Weigh the information and make a choice
  • Communicate the decision

Young people aged under 16 years

For young people under 16 there is precedent in case law governing consent to treatment. The law was set out in the case of Gillick (Gillick v West Norfolk and Wisbech AHA [1986] AC 112).

This states that if a minor has sufficient intelligence and understanding to enable him / her to understand the treatment and implications of treatment then he / she is ‘Gillick competent’ and can consent to treatment. (However a refusal of treatment may be treated differently - see below).  The Gillick case referred specifically to consent regarding contraceptive treatment and the guidance set out by Lord Fraser in the House of Lord’s Judgment in the case has been used as the template for determining whether to treat a young person without obtaining the consent of his or her parents. These are as follows:

The young person understands all aspects of the advice and its implications
The health care professional cannot persuade the young person to tell their parents or to allow the health professional to tell them
In relation to contraception and STIs, the young person is very likely to have sex with or without such treatment
Their physical or mental health is likely to suffer unless they receive such advice or treatment, and
It is in the best interests of the young person to receive the advice and treatment without parental knowledge or consent. 

For babies, young children and teenagers who are not competent in law someone else must consent on their behalf. This can be a proxy or the Court. A proxy is usually a parent or another person with parental responsibility. In making a decision about medical treatment the proxy must act in the child’s best interests and if this is not the case then the decision can be overridden by the court. Usually consent need be obtained from only one parent (although if treatment involves an operation that is irreversible and not medically necessary e.g. male circumcision and if the two parents disagree it is advisable to seek advice from the court). If there is a difference of opinion between the parent (s) and the clinician regarding best interests the matter can be referred to the Official Solicitor who is likely to make an application to the court. In an emergency situation, where a parent cannot be contacted, the child can be treated without consent, but only where treatment is immediately necessary.

Where consent cannot be obtained from an adult patient

The Mental Capacity Act 2005 and in Scotland the Adults with Incapacity (Scotland) Act 2000 provide that competent individuals over 18 (over 16 in Scotland)  can appoint someone to make decisions about medical treatment on their behalf if they become unable to do so. (Lasting Power of Attorney) If no such power of attorney has been executed then no-one can consent to or refuse treatment on behalf of an adult (over 18 in England, over 16 in Scotland).

There are two categories of situation where decisions about medical treatment need to be taken for incompetent patients:

  • When a patient is temporarily incompetent, e.g. if he/she is unconscious following an accident or acute medical event.
  • When a patient is unlikely ever to be able to make a competent decision about treatment, e.g. severe dementia or learning disability or permanent vegetative state.

In the first situation the healthcare professional should do no more than is necessary in the circumstances. This does NOT justify treatment that is against the known wishes of the patient. In both situations the health professional act in the best interests of the patient.  The principle of best interests also governs decisions made by Donees of Lasting Power of Attorney.

When Consent may not be needed - s63 Mental Health Act 1983

A patient who has been sectioned under the Mental Health Act may be treated without the requirement for consent. This is only applicable for treatment for the mental illness.

A more in depth discussion of treating adults who cannot consent can be found in the section on the Mental Capacity Act.

Refusal of Treatment


A competent adult may refuse treatment even if his/her life depends on it. The right to refuse treatment also applies to a pregnant woman even though the exercise of the right to refuse treatment may result in the death of her unborn child.

The English courts protect strenuously the right to be self-endangeringly eccentric, as these extracts from judgments illustrate:

“The patient is entitled to reject [the] advice for reasons which are rational, or irrational, or for no reason.” Per Lord Templeman in Sidaway v Board of Governors of Bethlem Royal Hospital [1985] 1 AC 171

“It is established that the principle of self-determination requires that respect must be given to the wishes of the patient, so that, if an adult patient of sound mind refuses, however unreasonably, to consent to treatment or care by which his life would or might be prolonged, the doctors responsible for his care must give effect to his wishes, even….though they do not consider it to be in his best interests to do so….” Per Lord Goff in Airedale NHS Trust v Bland [1993] AC 789.


A child who is competent can consent to treatment. However, a refusal of treatment may be overridden by a parent or the Court where such a refusal would be likely to result in the death or permanent disability of the child. Then the wishes of the child may be overridden to preserve his or her long-term interests.

Re M [1999] 2 FLR 1097

M was a competent 15 ½ year old who sustained acute heart failure and required a heart transplant. She stated that she did not want someone else’s heart and refused to give consent. It was considered to be in her best interests to have the transplant and (although she ultimately consented to the operation) it is clear that treatment would have been declared lawful despite a refusal.

Advance Statements

Advance statements about future medical treatment can be made by those who understand the implications of their choices in order to anticipate situations where they may lose mental capacity.

See End of life section and Mental Capacity Act section.