A living will allows you to declare that you do not wish to be kept alive by artificial means if (and only if) you are in a state of health where doctors determine there is no chance of recovery. You can make specific provisions for treatments and therapies such as artificial nutrition, painkillers, antibiotics, and more. Your living will is the first thing your healthcare surrogate will refer to if a decision needs to be made on your behalf.
A health care surrogate designation names someone to make health decisions for you if you are incapacitated due to illness, coma, or another medical condition. Your health care surrogate will carry out the requests from your living will, or, if unknown, will attempt to determine what you would want if you could communicate.
For many people, the health care surrogate is the same person named as agent in the power of attorney. However, the two documents cover two different areas–the health care surrogate only relates to medical decisions, but the power of attorney covers financial, insurance, and other activities.