More on KentOnline
They call it Sleeping Beauty Syndrome, a rare illness where people's heart rates slow and blood pressure drops suddenly.
To outsiders, it looks like the sufferer is tired and nodding off.
Harminder Samrai speaking about her platform, A Girl After My Own Heart and her condition
But it's a serious medical condition which has a debilitating effect on those living with it.
Harminder Samrai has battled the illness – official name reflex anoxic seizures (RAS) and vasovagal syncope – for most of her life.
Now, she has launched her own website to support teenage girls who also have "invisible disabilities".
The former Rochester grammar pupil's illness causes her to faint because her body overreacts to certain triggers.
This led her heart rate and blood pressure to drop suddenly.
People with the illness look like they have fallen asleep, hence the nickname Sleeping Beauty Syndrome.
The 25-year-old said: "I have had a heart condition since I was two, however, I wasn't diagnosed for 13 years.
"When I was younger I had random seizures, I would collapse and go pale and there was no symptoms and it would spontaneously happen.
"As a result I missed out on a lot of school, doctors thought it was epilepsy but my mum was certain it wasn't.
"I ended up being diagnosed with RAS, it looked like I was falling asleep but really my heart was stopping.
"They called it this so it was easier for me, a child at the time, to understand.
"Most people grow out of reflex anoxic seizures, but throughout my teens my condition worsened and I was diagnosed with vasovagal syncope, a more aggressive form of it.
At 14, Harminder was fitted with a pacemaker which generates electrical impulses to make the heart muscle chambers contract and pump blood.
She added: "There was a period where I was having episodes so frequently that when I did pass out the doctors saw that my heart was stopping.
"It is very much an invisible disability, it causes issues people can't see and it makes you feel isolated; people don't understand how you cope. That is why I created A Girl After My Own Heart."
The website aims to be a safe space for girls to socialise online and eventually in real life.
It's for late teens, giving them access to resources on mental health, and the ability to share their stories by working with Harminder and reading about how she has lived with the condition.
She added: "In the time of Covid-19, there is a wider awareness on invisible disabilities, and more of us are connecting and creating friendships through social media and blog pages.
"Many girls battle their hidden disabilities alone, and I know I'm not the only girl who has been in that position of dealing with health, being at school or university and making friends, it is really isolating and alienating.
"That is why I wanted to start lifting the veil on invisible disabilities, A Girl After My Own Heart really is about empowering those girls.
"I want it to help others not feel alone and isolated, school can be tough, I had to repeat Year 12 as a result of my disability."
Harminder began advocating for girls with invisible disabilities in 2012 and was a torch-bearer for the London Olympics.
She said: "When I was at school I was like an insurance risk, I wasn't allowed to go on trips because of my condition and I felt all alone.
"A Girl After My Own Heart will help girls in a similar position feel like they are part of a community.
"I wanted to make this platform to empower people, so girls can speak out about their disabilities without any stigma."
Harminder also contacted the British Heart Foundation about her health and platform.
The charity has now begun organising an upcoming podcast with her.
She said: "A big part for me about the platform is how it is visually, it is still growing and there is a very long way to go.
"I only published the site in March and decided to build it from scratch as I'm a bit of a perfectionist.
"I've learned how to do things through YouTube and it has given me the freedom to make immediate changes when I receive feedback.
"I also take my own images for the website, that was a learning curve.
"This website will allow girls to speak about their problems, their battles with mental health and see how others, including myself, have coped."
Harminder hopes in the future, medical professionals will suggest A Girl After My Own Heart as an avenue of support for young ladies when they are newly diagnosed.