Everyone, young or old, should have a Power of Attorney for Health Care decisions and a Power of Attorney for Financial Decisions so that they have a plan in place should they become disabled by illness or accident. A Power of Attorney will go to the person that YOU choose to make decisions for you. A Power of Attorney for Health Care generally would only be activated when two doctors decide that you are unable to communicate your wishes. Until that point, YOU remain in charge of the decision-making. A Power of Attorney for Financial Decisions may be necessary because of illness or it may be more convenient to have someone else help you manage your finances. Or you may simply want to travel and still make sure someone is paying your bills and satching out for your property back home.
If you become ill or disabled and do not have a Power of Attorney, then the local Probate Court may have to appoint a Guardian or Conservator to make decisions and take charge of your assets. This will be someone the Court chooses. It will not necessarily be the person YOU would have picked. If you have a Power of Attorney, the Probate Court would have to honor the choices you made.