An advance directive outlines what wishes your doctor must follow if you become unable to make your own medical decisions. When you're admitted to the hospital usually the staff will ask you if you have an advance direct, or you can hand your doctor and hospital staff a copy yourself if they do not ask.
An ideal advance directive would be to describe the kind of treatment you would want depending on how sick you are at the time. Also, an advance directive is made to describe what to do if you have an illness that you most likely have no chance to recover from, or if your in a coma what kind of care you wish. The most important thing on an advance directive is what you do not want your doctor to do otherwise a doctor will usually do everything in his power he fees is necessary. However it works both ways, you can demand certain treatments no matter how ill you become.
The laws and forms on advance directives are usually different for every state, its important you get your state's specific form that conforms to your state's laws.
The good thing about an advance direct is that you do not stress out your family and loved ones by putting the burden of making medical decisions for you. If your 18 years or over you can prepare an advance directive.
A do not resuscitate order is like an advance direct but very specific. A do not resuscitate order is made for you to request if you want cardiopulmonary resuscitation (CPR). Usually if you do not fill this form out the whole hospital staff is trained in CPR and also trained to revive you using CPR if your heart stops or you stop breathing. Do not resuscitate orders are accepted in all states.