Where do I start? My mum is 80, blind and living with my dad. She sends very angry, and bizarre emails. Her behaviour is escalating.

Yoy can get forms from your attorney general's website and or the supreme court website. Be sure that someone has a Durable POA this covers more and is accepted more readily.

I am so sorry your family is facing this challenge.

HIPPA is a form signed by parent and directed to other health providers that gives the health provider the right to talk about their issues with you and/or your sister, avoiding the 'privacy' problems that many health providers get their knickers in a knot about. I am not legally qualified in the USA, so I hope some others will fill in more details about the forms needed. You should be able to get the HIPPA form and bring it home for signature, perhaps getting one for your father too and asking him to get them both signed as 'just one of those formalities'. If you can't get it in place before the first doctor's appointment, it is a good idea to write to the doctor putting him/her on notice about the problems. You won't get an answer, but the doctor will probably handle the appointment differently.

As your mother is not on good terms with you and your sister, your father may also have the best chance of getting mother along to a doctor's appointment. He could make up a reason (flu injection? a nasty spot on your back that you can't see, dear, but it's worrying me?), or just ask her to come with him to his own appointment for support because he is so worried that he might have bubonic plague. (I'll leave the detail up to you!)

I can guess that the diagnosis seems the most important thing at present, but please at least consider getting the paperwork in place first. Once a 'not competent' diagnosis is made you can't go back. Even if she is not really competent now, you should be able to wing it before the formal medical decision is made. There must be a place on this site explaining all the paperwork, but it's not relevant for me so I have never chased it up. The detailed rules (even the labels for things) are inconsistent from state to state in the USA, so you need local information.

Best wishes, and keep asking.

Before you get a diagnosis, it is worthwhile checking if you have all the bits of paper in place – POA, HIPPA, appropriate will appointing an appropriate executor, end of life care directive etc. Once she is diagnosed as not competent, it is too late to get them done, and this could be a big problem. If your father has been appointed to POA etc, make sure that there is a process for replacing him in the future, as he is not getting any younger either.

Part of the preliminary stuff is of course to talk to your father. What has he noticed, when, how quickly are things progressing? You are fortunate that he already thinks that she is ‘losing the plot’, which should make the talk more helpful and less stressful for both of you. Then find out what he thinks is the best way forward, for your mother and also for himself. Options are aides for in-home care, independent living, assisted living, nursing home and nursing home/ memory care – quite possibly not the first three, unless you want a place where they can both to together with separate levels of care.

Then go ahead with doctors to get the diagnosis. Other people may disagree with the priority of these steps, but that’s the way I would go. If you want feedback and suggestions about the options you are looking at, write again.