Extract from Compassion in Dying's website:
What do an Advance Decision (Living Will) and an LPA cover?
An Advance Decision covers refusals of medical treatment. It also only applies to the treatments and circumstances that you write about in the form. It won’t apply if you’re in a situation that isn’t covered in your Advance Decision.
An LPA allows your attorney to make any decision about your health and personal welfare. This includes where you live and how you’re cared for, your diet and what you wear as well as decisions about medical treatment.
Who makes decisions for me if I make an Advance Decision (Living Will) or an LPA?
In an Advance Decision, you make a refusal of medical treatment. It’s in your own words.
In an LPA, your attorney will make decisions on your behalf. You therefore need to trust your attorney to understand your wishes, respect your values and be able to make the best decisions for you.
How much does it cost to make an Advance Decision (Living Will) and an LPA?
It’s free to make an Advance Decision. It currently costs £82 to register an LPA, but some people with low incomes or on certain benefits can pay a reduced fee.
Trisher, it seems that whereas the Advance decision form requires some detail, the other form the Lasting Power of |Attorney for Health and Welfare can decide as if they were you yourself.
I see that Compassion in Dying say that AgeUK will send a knowledgeable volunteer to help with these forms. My son helped me with the Power of |Attorney for financial stuff and he is good at such things however there will be people who feel they need help from someone else.