A new Alzheimer's Australia campaign is urging people to "choose it or lose it".
The Start2Talk online campaign encourages everyone to talk to their loved ones about their future healthcare, lifestyle and financial decisions, while they are still able to do so.
Project manager Dr Chris Shanley said the website had been developed after community consultations revealed there was a lack of "planning ahead" tools available, making it hard for people to document their wishes.
"We talked to carers and people in the early stages of dementia who were frustrated by the difficulties involved in planning for the future," he said.
"They wanted something that was user-friendly and that was national in scope as differing state and territory laws was making it that much more difficult."
Dr Shanley said the website (Start2Talk.org.au) gave people information and tools to help them make their wishes known.
It included worksheets people could work through - on their own or with a loved one - and file away with their papers or online.
"All of us want to make our own decisions but many of us get to a point where other people have to make decisions on our behalf," he said.
"It can be quite stressful for those people if they don't know the wishes of their loved ones and it can cause disharmony or conflict in families.
"So it's important for all of us to make our wishes known, so they are followed through should we ever be in a position where we can't talk or make our own decisions."
Alzheimer's Australia Illawarra project officer Mary Bills said about 50 people attended the recent launch of the project in Kiama.
"The local launch was designed to spark conversation as a lot of people find it hard to discuss the possibility of not being able to make their own decisions," she said.
"However, it's important to have these conversations early as they become even harder when someone is diagnosed with dementia or another illness that may affect their ability or capacity to make those decisions themselves."
Woonona resident Debbie Ryan-Agnew made one of the hardest decisions of her life when she placed her friend of 35 years into a nursing home.
The decision was made easier by the fact that her friend, Eileen Wood, had made the decision for herself before her dementia.
"After her husband died over 10 years ago she asked me if I would be able to make the decisions for her if she was no longer able to do so herself," Mrs Ryan-Agnew said.
"She had no children and thought that as a nurse I would be the best placed to make decisions about her care.
"It's a hard conversation to have, but I'm glad that we were able to have it when we did."
An enduring guardianship followed, and was only acted upon when Mrs Wood was diagnosed with vascular dementia.
"Around two or three years ago she started to get a bit wicked in her comments, a bit rude, and then she started to get some memory loss," Mrs Ryan-Agnew said.
"She lived in an area of Sydney that was quite isolated and when she became unwell I organised some healthcare services for her but she still seemed relatively safe on her own.
"It was only during one visit, when I found her in a delirium as she had not taken her medication for some time, that I knew something had to be done."
Mrs Ryan-Agnew said her friend, 88, became angry when the decision was made, but several months later was settling in well.
"She told me she was disappointed in me, which broke my heart, but I took comfort in the fact that it's what she told me she wanted. People need to talk more about these issues - we all think we're going to live forever and be able to make our own decisions but as a nurse of 35 years I know that's not the reality."