For most people thinking about the end of their own lives is psychologically difficult. This has stopped many from getting living wills and other advanced directives, such as powers of attorney. People do not like to think about the possibility that at some point in the future they may not be able to make their own decisions and that they might even be ill enough that they do not want doctors to take steps to extend their lives.
That is understandable.
However, as Psychology Today points out in "Putting It in Writing," it is important to think about and get a living will (aka Advance Health Care Directive).
The biggest benefit to making the effort to get a living will is you cannot do it later. You cannot put off getting a living will until you need it. By definition, when you actually need the document you are not legally able to get it.
Thus, if you want to have a say in what measures doctors will take to prolong your life when you are unable to tell them your wishes, then you need to do that ahead of time. There is also a benefit in that having the document can give you peace of mind that you have taken the appropriate steps to ensure your wishes will be carried out.
If you do not have a living will or other advanced medical directives, schedule an appointment with an estate planning attorney and get it done while you can.
Reference: Psychology Today (April 7, 2016) "Putting It in Writing"