Most all adults make their own decisions about medical treatment on their own–their body, their choice.
In Michigan, if you are over 18 years old, and you haven’t prepared a designation of patient advocate form and/or a medical power of attorney form, all hell can break loose should you become so disabled that two doctors think you cannot effectively communicate your treatment wishes.
And this is so even though you might have loving parents or a sibling or even a spouse.  They are not allowed, under law, to automatically speak for you except under rare and unusual circumstances. So no one really directs your medical care when you cannot speak for yourself until a guardian is appointed.
This surprises most non-attorneys, who tend to assume that others could speak for them under such circumstances.
In reality, unless you have already established a valid designation of patient advocate form or valid (under Michigan law) medical power of attorney, a trip to the local probate court will likely be required. (Get a checkbook out for the filing fee, and plan to wait a day or so if an emergency petition, or a few weeks if a typical non-emergency adult guardianship petition.  And expect those around you to be frustrated and dismayed a bit, that they had to go through this at all.)
The Michigan Legislature publishes a booklet called “Planning for Your Peace of Mind” and you can find it here:
http://www.legislature.mi.gov/Publications/PeaceofMind.pdf
At a minimum, take care of that basic step yourself.
It would also be smart, really, to do more with a complete medical power of attorney drafted with your very own circumstances in mind–especially since Michigan’s specific designation of patient advocate law really only lets someone step in under pretty extreme circumstances.
But at least you’d have a start.
And of course, many fine attorneys can help you get further down the road towards careful planning and document drafting.
It would be prudent to make an appointment–while it is an appointment to create a document we never hope to need (I’m planning to die in my sleep with no medical involvement at age 100 myself–what about you? :-)) you just never know.
Don’t leave your friends and family up the creek without a paddle–plan now.