This Practice Note deals with the principle of self-determination, valid consent, implied consent, sufficient information in accordance with Montgomery, and causation.

Treatment of a patient by a doctor requires prior consent in order to be lawful. This is so whether the treatment is a simple test or an invasive operation. In practice, issues of consent will only tend to arise following more serious and risky kinds of treatment such as surgery.

Every adult with the necessary mental capacity to make their own treatment decisions has the right to decide whether or not they will accept treatment, even if refusal risks permanent injury or death to them or their unborn child. Nor can that treatment be legitimised by detaining them as a mental patient.

For further consent issues such as emergency treatment, withdrawal of consent, capacity, professional guidance, battery and Human Rights Act 1998 claims, see Practice Note: Consent in clinical negligence claims—capacity and other issues.