When you choose your healthcare agent, you can limit that person's authority to a specific period of time (days, weeks, or months). You might choose to do this if, for example, you know your healthcare agent will be moving in the future or will become unavailable for some reason. You can also limit the agent's authority to specific medical treatment decisions. MyDirectives walks you through these options.
Even if you have a healthcare agent, you still have complete control over all of your healthcare decisions unless, and until, doctors decide you can't make or communicate decisions for yourself, or a court declares you to be incompetent.
You should know that your healthcare agent has no power over decisions that aren't related to medical treatment, such as finances, work-related issues, funeral matters, and anything that might be covered in your will.