If you are worried about being medically treated when you are unconscious, or have strong feelings about the treatment you do not wish to get, you may want to make an advance decision, sometimes referred to as a living will. You must be deemed to have capacity at the time you wish to make the advance decision. It can also be cancelled or altered at any time when you still have the capacity to do so.
You should let your immediate family and your doctor know about your advance decision (living will).
This is a legally binding decision about things like getting a blood transfusion, organ transplant or being fed through a tube. It will be upheld in a situation where you are unable to make an informed choice because you are unconscious, you have a learning disability or an illness like dementia. An advance decision (living will) to refuse treatment for mental disorder can be overruled if the person is detained in hospital under the Mental Health Act.
You can also make a written statement with details of your dietary preferences, religious or cultural preferences for your end of life care. Such written statements are not legally binding but health and social workers should take them into account when planning your care.
Compassion in Dying has downloadable advance decision forms and more information about living wills.