Dementia affects about 70,000 Kiwis and it's usually associated with the elderly.
But that's not always the case. It can affect kids - and one mum in Australia has made headlines after she revealed three of her young children have it.
Every three seconds, someone in the world is diagnosed with dementia. Australian mum Renee Staska never expected her three young children to be among them.
"Everyone thinks that tomorrow is a given but it's not, so we just get through one day at a time," she said.
Aged just eight, six, and four, Hudson, Holly, and Austin all have childhood dementia and it's unlikely they will make their 20th birthday.
"I was given it on a piece of paper and said, 'This is what it is, there's no treatment, there's no cure'," Staska said. "I cried and I cried and very soon we were introduced to palliative care, which I wasn't even aware was a thing for children."
About 700,000 children worldwide have childhood dementia and Newshub knows of at least one young child with it in New Zealand. All up, the disease affects about 50 million people of all ages.
In New Zealand, about 70,000 Kiwis are living with dementia today. but this will likely increase to 170,000 by 2050. Most patients here are over the age of 65 and it does affect more women than men. The cost to the country is about $2.5 billion.
So put simply, what is dementia?
"Dementia is a condition that affects two or more modes of cognition. It could be language, it could be memory, it could be attention, it could be forward planning. There are many kinds of dementia," explained dementia specialist Dr Owen Jones. "But the type of dementia you could develop would depend on which part of the brain is under attack. And depending on which part of the brain is afflicted, that will manifest in different modes of cognition being lost."
Dr Jones has been awarded a Neurological Foundation grant to further study dementia here. He said social isolation can increase a person's risk profile and the COVID-19 pandemic certainly hasn't helped.
"The theory goes that when you are socially isolated, when you are disengaged with your community, from the world around you, you are simply using your brain less and when you are not practising using those brain pathways, they are more at risk of being eroded by the disease," he said.
Symptoms can vary greatly, but the most obvious early ones are memory loss, poor judgment, and confusion. For some patients, it can be a scary, lonely world.
When it comes to prevention, exercise and a good diet can certainly help.
"Some of the things that people might not be aware of, though, are like protecting your senses. It's estimated that about 8 or 9 percent of cases of dementia worldwide are due to hearing loss," Dr Jones said. "However, that risk goes away if you happen to wear a hearing aid. So looking after your ears is looking after your brain. The same might be said for vision."
But there is no cure for dementia and one in four Kiwis will die with it.
"So many of us can get dementia and it's just a very, very sad thing," said Judy Jetten.
Jetten, 85, wants to help - her best friend has dementia. The retired dressmaker is creating knitted twiddle muffs, which are a visual and tactile sensory stimulation for patients.
"It's a very old English thing, because there are things inside ... They sit there and they twiddle, they twiddle," Jetten said. "It keeps them busy instead of picking at their body."
She has already created 25 muffs, which are used by elderly dementia patients at her Fairview Lifestyle Village and nearby hospitals.
"One of the biggest things about dementia is it can be about sensory overload. Simple things like this can bring them back down, bring them back to reality a little bit. It does help, it does help a lot," said Fairview Lifestyle Village nurse Benjamin Peattie.
Because those fleeting moments of lucidity can be powerful, not just for the patients but for their loved ones too.
