Many of us have experienced the heartache of watching a loved-one suffer from dementia, but the illness isn't an inevitable part of ageing.
In the thought-provoking video above, actor Christopher Eccleston reminds us of the causes of dementia and how researchers hope to one day beat the disease.
Eccleston, whose father Ronnie died following a 14-year battle with dementia, teamed up with Alzheimer's Research UK to create the clip.
"Like many of you I've witnessed the devastating effects of dementia. But because many people think dementia is just a natural part of ageing, they don't realise that it's something that we could one day defeat," he says in the film.
To help change public perceptions surrounding dementia, Eccleston asks viewers to share the video on social media along with the hashtag #ShareTheOrange.
"The truth is, dementia is actually caused by diseases, just like cancer or AIDS," he explains.
"Alzheimer's disease is the biggest cause of dementia. It physically attacks your brain, gradually destroying it piece, by piece, by piece, until it strips away everything that makes you, you. "
According to Eccleston, the brain of a person with Alzheimer's disease is so damaged it weighs around 40g less than a healthy brain. That's about the weight of an orange.
"While scary, this does prove that it's a physical disease and not just part of ageing," he said. "Research has beaten diseases in the past. And with your help, research can defeat dementia."
To find out more about Alzheimer's disease and dementia visit Alzheimer's UK.
