The best-laid plans can go astray. For estate planning purposes, the main complication as you grow older may be the condition of your health. Even if you’ve been healthy your entire life, you may suddenly be struck by a debilitating illness or injury.

Fortunately, you can take precautions relating to your future health care by preparing health care directives for your family and physicians to follow. But the legal documents used in planning could contradict each other or otherwise lead to confusion.  

The two main types of directives to consider are:

A living will. This states when treatment should be withdrawn or continued when you’re terminally ill or unconscious. However, these documents can be misinterpreted by physicians and other professionals or may be too vague to be of much use.

A durable health care power of attorney. Also referred to as a health care proxy, this appoints someone to act on your behalf regarding your health care decisions. It generally assigns more responsibility to the designated agent than a living will does as to end-of-life decisions.

Other health-care-related instructions may be included in a regular will, but a living will or power of attorney may supersede the will, based on state law. Also, you may indicate your health care preferences in a letter of instruction accompanying your will, but that document has no legal authority.

The best approach is to coordinate all your relevant estate planning documents to provide a clear approach for your situation. Make sure that everyone concerned is on the same page as far as the direction you want to take.