Hannah was 13 when she started seeing figures and hearing voices as she was nodding off to sleep.

Hannah Cross had always been one of those kids whose sleep was slightly wonky.

She remembers laying awake at night a lot as a kid, while also having the ability to sleep anywhere at the drop of a hat. 

By the time she was thirteen the 'sleepiness' had started to increase, and with it came voices and visions that would startle her back awake if she ever started to nod off. 

WATCH: Hannah on being diagnosed aged 28. Post continues after video.

Sometimes surfaces would move like a rippling piece of fabric. 

Sometimes she'd see spaceships, or weird pieces of machinery, or hundreds of animals running beside her, or figures without faces. One time she saw a woman in an ornate red dress climbing out of a mirror levitating in the middle of the room. 

Other times it was sounds. Heavy breathing in her ear, or someone shouting her name.

"I knew from the get go the sounds and visions weren't real in an objective sense even though they were very real for me. I came to understand them as my body's way of trying to wake me up," Hannah told Mamamia.

"There was always a feature of them that was quite surreal...they were almost aura-like," she added. 

From the outside, Hannah appeared to be a pretty well adjusted teenage girl who was getting good grades and participating in school activities just like everyone else. But on the inside, the visions were taking a toll on her mental health, and her tiredness and need to fall asleep led to feelings of shame. 

During highschool, Hannah started hearing voices and having hallucinations. Image: Supplied. 

"I became extremely anxious trying to scan for these symptoms or predict when they'd come on. They were by their nature very unpredictable. It became this constant state of being on the lookout for myself," she said. 

She never really told anyone about the intricacies of her hallucinations, because often others would just perceive her 'sleepiness' as a weakness, or a lack of willpower. She also just assumed everyone to some extent 'saw' strange things. 

Over the years Hannah's visions ranged from beautiful to psychedelic to really disturbing, and they got more and more frequent as she got older. 

By the time she was in her early 20s they were a daily occurrence.

There was one vision she would get a lot while driving - a man dressed in grey pants and a grey hoodie standing on the side of the road. 

"He'd always be standing three feet above the ground and if I was about to have an episode, he'd jump in front of my car," she said.

It was also in her early 20s that the more tactile hallucinations started to emerge, and it was these that eventually saw her sitting in her GP's office telling a medical professional for the first time about what she'd been experiencing.

"I could feel people touching or grabbing me... or putting their hands around my neck. That was pretty awful," she told Mamamia. 

"I would also feel people sitting on the bed...so the feeling of weight shifting. Or breathing on my face," she added.

The doctor, who only had a 15-minute session with Hannah, misdiagnosed her as just having depression and anxiety but made an offhand comment that it could also "possibly be schizophrenia," while handing over some antidepressants and suggesting she "try these first."

The flippancy of the comment turned Hannah off wanting to investigate her symptoms for a few years, so it wasn't until she was 28 that she was officially diagnosed.

Hannah wasn't diagnosed until she was 28. Image: SBS/Supplied.

Studying medicine at the time, she fell off her chair after falling asleep during her GP placement and her supervisor made an armchair assessment and sent her off to a sleep specialist, where she was told she had narcolepsy and cataplexy.

Narcolepsy is a chronic sleep disorder characterised by overwhelming daytime drowsiness and sudden attacks of sleep, while cataplexy is when your muscles suddenly go limp or weaken without warning when you feel a strong emotion. 

"For me, my experiences with voices and visual hallucinations are often kind of a prodrome. So sometimes I will see and hear things before I have an episode. Or sometimes if I push through the fatigue or cataplexy then I tend to have quite intense hallucinations for a time after that," Hannah told SBS Insight.



"It was a huge relief [to get a diagnosis] even though it does suck to have something that can't be fixed. But it can be managed.. and that's where I got the relief," Hannah told Mamamia.

The biggest relief of all though, was finally being believed. 

"Having someone else see and acknowledge that there was a problem and not feeling like I was making it up. Or that I wasn't trying hard enough...or just not sleeping well enough," she said. 

Nowadays Hannah has her symptoms pretty well under control and is no longer getting daily hallucinations. 

"I still get breakthrough symptoms. More of the cataplexy though... so I lose tone. Or I fall asleep suddenly if I am distressed or anxious," said the now 34-year-old. 

Hannah is now a senior psychiatric registrar and is working with other patients who hear voices, an area of medicine she feels passionate about as she continues to understand her own experiences. 

"If your kids keep coming to you with a problem, pay attention," she told Mamamia.

"Not everything should be pathologised. There are just imaginative kids out there of course. But with most things, if there's an element of distress, that's the stuff that needs to be looked at," she said. 

Feature image: Supplied/SBS.

You can hear more from Hannah on SBS Insight tonight at 8.30pm.