Chris Hemsworth reveals key Alzheimer's signs to be aware of after dad's heartbreaking diagnosis

Chris Hemsworth has opened up on his dad's Alzheimer's diagnosis and the initial signs he was 'concerned' about.

The Marvel star, 42, revealed last year that his dad Craig, 70, had been diagnosed with the disease as they travelled throughout Australia together for their TV show, A Road Trip To Remember.

The father-son duo revisited Craig's childhood homes, with Hemsworth emotionally 'designing a road trip back in time, revisiting key places from their past to explore the science of social connection and how it can support memory function'.

And recently, speaking to The Guardian, the Thor actor explained that opened up about his dad's health to the world wasn't exactly easy.

Hemsworth said: "I wondered if I was letting people too far in. Are they no longer going to believe in the action star or the Marvel character? And do I want people to know my fears and insecurities to this level?'

In November, Chris Hemsworth revealed the first signs that his dad had Alzheimer's (Stephane Cardinale - Corbis / Contributor / via Getty Images)

"It was so deeply personal. It was a love letter to my father. It empowered him for a period, and stimulated memories that were being taken away from him."

In November, Hemsworth appeared on Jay Shetty's podcast On Purpose, where he admitted that his dad's diagnosis had been a 'real shock to the system' for his family.

He also gave an insight into some of the first 'signs' he and his family began to notice that something wasn't right.

The actor recalled: "I remember vividly that conversation of him sort of telling me not to be concerned about it

"And then about two or three years later, my mum's saying to me, 'I think we've got to get dad checked because there's these signs and things I'm concerned about'."

He continued: "The obvious one's memory and sort of slight mood, changes and shifts and forgetfulness and so on. So he went and got tested and found out he had two copies of the APOE4 four, as did my mum."

Hemsworth explained that by default, he has two copies of APOE4 - the gene that may increase your risk of developing Alzheimer's disease.

"I was immediately hit with the reality of what that meant for him because I had just gone through 'Ah it's a long way down the track, don't worry, push it aside'," he said, before adding: "Then all of a sudden it was right in front of us and, and it was confronting, but again, I think 'we'll figure it out mentality' was still very prominent.

The Marvel actor noted how his dad's diagnosis was 'a real shock to the system' (Mike Marsland / Contributor / via Getty Images)

"But then as it began to get worse it became a real sort of shaking into the moment and a real sort of shock to the system."

Hemsworth recalled: "Everything we thought was solid and true and consistent was gonna dramatically change and shift."

The actor also touched on this during the first of his National Geographic projects in 2022 - a documentary series called Limitless.

In the programme, he looked into his family's history of Alzheimer's disease as his maternal grandfather had the disorder.

This is when he found out that he is eight to 10 times more likely to develop the condition than average person due to having two copies of the APOE4 gene.

If you've been affected by dementia or Alzheimer's and would like to speak with someone in confidence, contact the Alzheimer’s Society via 0333 150 3456 or visit their website for more information.