A rare disease means this model suffers from mini strokes, any of which could turn into a real one.

Two years ago, when she was just 17, Liz Bos was sitting at home typing up a uni assignment when she suddenly lost the use of her left hand. The sensation was gone; her fingers, useless.

The Brisbane teen’s mother rushed her to hospital, but baffled doctors had no answers. Then lying awake that night, she overheard the doctor and the radiologist talking to one another, and one mentioned something called Moyamoya Disease.

It was a conversation that would change – and save – her life.

“When my mum came back to the hospital, I mentioned the name and she jumped on Google straight away and read about how awful it was, and so she contacted my doctor in Sydney,” she told Mamamia. “In the next couple of days we flew over, and a couple of days after that I got booked in for emergency surgery.”

Liz only discovered she has Moyamoya when she was 17. Image: supplied.

Moyamoya Disease is a rare vascular disorder that causes blockages in the arteries at the base of the brain. Only 1 in 200,000 people worldwide are believed to suffer from it, and there is no cure - just preventative treatment.

In Liz's case, that was an emergency operation to alleviate a blockage in the middle cerebral artery.

“I didn’t really have time to get scared about it because it all happened so quickly," she sad. "It didn’t really sink in until after the surgery, so it’s kind of good that it happened like that in a way.”

While that primary blockage was fixed, Liz is one of the unfortunate few to also suffer from blockages in both the anterior arteries as well - something virtually impossible to fix in adults.

The result are transient ischaemic attacks, which are essentially mini-strokes that can occur as often as every two days. These temporarily halt blood flow to parts of the brain, and in Liz's case, cause weakness in her legs, sharp headaches and impact her vision and speech. She's also constantly fatigued.

"I usually find it’s when my blood pressure is lower. So if I haven’t been drinking a lot of fluids, if I’ve been sitting or lying down, or I’m in the shower, or something like that, that’s when it’s more likely to happen," she said.

“You get used to it. That becomes your normal. I don’t notice it as much as I used to because I’ve been experiencing it for that long.”

Liz Bos' strokes usually occur when she's relaxed. Image: Facebook.

These attacks generally last for anywhere between 30 seconds to a minute. But, as she discovered last July, they can last for much longer.

"I was at work, and I started to feel dizzy and faint. Then my legs just wouldn’t work," she said.

"It doesn’t feel like they’re numb; it just feels like they’re not there at all. I could not make any contact from my brain to my legs for over four hours.

"I ended up in the hospital and [the doctors] were like, ‘Look, they haven’t moved for so many hours, we’re not sure if they’re going to come back.’ You never can tell with these things. Even a mini stroke could turn into a real one."

Thankfully she recovered, but it's an event that's altered her perspective on her health and her body.

"People don’t understand how lucky they are to have a fully functioning brain and body," she said. "It just makes me more grateful that everyday everyday I wake up and everything is moving properly.”

Liz is currently studying an honours degree in Law at Queensland University of Technology, and squeezes in bar and modelling work in between.

“To be honest, I think it’s all about mindset, I’m not one of those people to dwell on it and let it get to me. I just figure there’s no point worry about it because it won’t help anything," she said.

"I’d rather just focus on the things I have and the things I can do, rather than the things I can’t.”

So set is she in that approach, most wouldn't know she's even know she has the condition. And for Liz, that's actually part of the problem.

“It’s important to me to show people that disabilities aren’t always visible," she said.

“Especially with Moyamoya Disease, because so few people have it, I actually prefer to tell people about it.

"Awareness is such a big thing. There’s no awareness, so there’s no cure."

This November the Stroke Foundation is calling on the community to get moving and Stride4stroke. Stride4stroke participants are encouraged to pledge a kilometre target for the month and get out there and get moving. Find out more at strokefoundation.org.au.