Dementia services need to be urgently addressed if they are to meet future demand, a watchdog has said.
The National Audit Office has criticised the NHS for lagging behind other countries when it comes to early diagnosis.
Dave Edmonds was 54 when he was diagnosed
It was on a year-long round-the-world trip six years ago that Dawn Edmonds began to suspect something was wrong with her husband Dave.
He had started to struggle to sign his signature and used to get lost on his way back to their hotels.
And then he forgot how to swim. Ms Edmonds, 51, from Shropshire, said: "We were in Thailand and he jumped in the sea but just sank.
"I had to drag him out and he said he could not remember how to swim. That was a turning point."
Soon after reaching Australia on the next leg of their tour, they decided to cut short their holiday and head back to England to see doctors.
Once back home, they consulted their local GP.
"We thought we would be given support and advice, but really got nothing. We were just fobbed off and decided we would have to pay privately to find out what was happening.
"I did ask if it was dementia, but we were just told Dave was too young, he was only 54."
However, the private consultation revealed it was just that.
Again, they went to see their GP, this time to see what treatment Mr Edmonds could get.
Mrs Edmonds said: "He told us there was a drug available, but Dave couldn't have it. He never gave us a reason and we just walked out of there in a state of shock.
"But we soon decided we were not going to let it rest there and so contacted doctors outside our area."
They eventually got to see a consultant working elsewhere in the Midlands, who gave Mr Edmonds a prescription for Alzheimer's drug Aricept.
Father-of-two Mr Edmonds, who worked as a chartered accountant before selling his business to go on the round-the-world trip, has been on the treatment ever since.
He has recently been admitted to hospital after his condition deteriorated, but Mrs Edmonds said up until the start of this year her husband has had an excellent quality of life.
"Dave has been on holidays, he has had a social life.
"None of that would have been possible if we had not got the diagnosis when we did and the drugs from the start.
"But it wasn't thanks to the NHS. We had to fight for it all the way, it is an insult."