One in five people in the UK have a disability - with 80% of those having a hidden disability.
When disabilities are not visible, it can mean people struggle to access the help and treatment they need.
"People assume it's not there," said Helena Thornton, who has non-epileptic attack disorder - also known as functional neurological disorder.
But at first she did not even realise the disorder meant she had a disability.
"I had a really traditional view of what a disability looked like," she said.
"I had no idea that there were accommodations that could be put in place to make things easier.
Helena Thornton from Bristol talks about living with a hidden disability
“Things were just going wrong for me and I didn’t realise that there were just alternative ways of doing them that were more accommodating.”
She said at first she worried she was "taking away" from others with more visible disabilities - but has now realised that is not the case.
"I'm now quite vocal about it," she said.
There are 14 million disabled people in the UK, around 11 million of those people have a hidden disability.
Hidden disabilities are physical and mental conditions which impact a person's day-to-day life, including but not limited to autism, learning disabilities, mental and physical health conditions, hearing loss, visual impairments, chronic pain and a range of other conditions.
Laith Alobaidi, from Budleigh Salterton in Devon, is one of those people.
The 26-year-old was diagnosed with inflammatory bowel condition Crohn's disease three years ago.
'There's definitely a lack of understanding'
Symptoms of Crohn's include needing the toilet frequently, fatigue, weight loss and pain.
Speaking to ITV News, he said he finds people take his disability less seriously because it is not visible.
He said hidden disabilities are a "subject that once raised, tend to be swept under the carpet or pushed to one side".
"There’s definitely a lack of understanding which leads to quite poor discourse - in any walk of life - my friends, my family, work in particular," he said.
"It can vary individual to individual based on their personal experience, but in terms of a wider conversation, I don’t think it is really had to be honest.”
It has also impacted his work. He said: “I was taking a lot of time off work - several weeks at a time - trying to come back and continue. So I ended up having to quit the job for a little while to try and recover my health."
How to support people with a hidden disability
Helena says a key difference to helping people with hidden disabilities is educating the public.
She said: “Having the wider public be more educated on hidden disabilities is so important.
“Having schemes like the sunflower lanyard scheme recognised, so people know there are ways people can communicate they might need extra assistance or have an impairment, without needing to go out and say it at the beginning of every conversation is important."
She said it is key that people react well when others disclose they have a hidden disability so they are not put off doing so again in the future.
"People are getting better at understanding that hidden disabilities are a thing, that they're not just any one thing as well - that there's a huge range of hidden disabilities and they are actually quite common."