No matter how carefully you plan for the future and how well you fill out your advance care plan, you can't know ahead of time everything you might face. A healthcare agent makes decisions in times of crisis when you can't make or communicate your medical treatment goals, preferences and priorities, or when a court declares you to be incompetent, and your expressed wishes don't cover the situation.
People tend to think that choosing a healthcare agent is something only people who are elderly, frail, or chronically or terminally ill need to think about. But a serious accident can happen at any time no matter your age. If you're seriously injured or become so sick that you can't make and communicate your treatment goals, preferences and priorities, a healthcare agent speaks for you and makes medical treatment decisions on your behalf. The healthcare agent can make sure you get treatment that goes along with your values, beliefs, and wishes.