I have harped on this matter before so I won't ramble on too much about it today.
I just think it is very important for us to give some thought and discussion to how we would want to be cared for in the case of a medical emergency, and what are wishes might be for resuscitation, organ donation, and life support.
Working in the emergency department I have had the unfortunate opportunity to witness families struggling with these decisions on behalf of their loved one who has suddenly become incapable of making their own choices regarding heath care interventions.
Even if you are a young person you ought to let your family know your end of life wishes, like organ donation or not, and what measures you'd like taken to keep you alive.
It is an uncomfortable topic but will give some relief to your loved ones if they at least have an idea of what you'd want, should an unfortunate circumstance befall you.
Take a moment and look at these websites for some guidance in making your wishes known.
http://engagewithgrace.org/ and http://www.nationalhealthcaredecisionsday.org/
And if you want a worst case scenario of what really can happen, wander over to Dr. Grumpy's blog and see how it impacts not only the family of those involved, but also the health care workers. This is an important post on the matter.