In the UK, you may have created an Enduring Power of Attorney prior to October 2007…
If you did this can still be used (as long as it was signed correctly and is legal!).
An Enduring Power of Attorney only relates to Property & Financial Affairs and so any Attorney appointed cannot take Health & Welfare decisions, a Lasting Power of Attorney must be put in place to do this.
An Enduring Power of Attorney can be used whilst you still have capacity if you would like your Attorney to act for you BUT once you have lost capacity it MUST be registered.