"My head gets really hot, my heart rate goes up and all these horrible thoughts go through my head like 'how do I get out?'"
Rochelle Bisson (not pictured) describes having a panic or anxiety attack.
Anxiety is a mental disorder that can wreak havoc. When it builds up it can lead to a panic attack.
Rochelle, who's 24, says most people are supportive but many still don't understand.
"They say things like 'you just need to calm down'."
Last week, Pete Doherty suffered a "serious anxiety attack" which forced the Libertines to cancel a Radio 1 Live Lounge appearance and gigs in London and Manchester.
Rochelle's attacks began two years ago when she got her first job after university and was commuting by train into London.
"I developed a severe phobia of packed trains, it was the fear of being trapped. One time it happened on the tube. It stopped in between stations.
"All these horrible thoughts go through my head like 'how do I get out?' 'What if I can't get out?'
The term "anxiety attack" does not have a strictly defined meaning according to Stephen Buckley, from the mental health charity Mind.
"People tend to use it either interchangeably with the term 'panic attack', or to describe feelings associated with an overwhelming build-up of anxious feelings," he says.
An attack can be described as an exaggeration of your body's normal response to fear, stress or excitement. Symptoms can include physical sensations like sweating, shaking limbs and feeling faint.
During the experience you might feel like you're losing control or even as though you're going to die.
Sufferers often feel as though their symptoms are either not taken seriously or that they're often shrugged off.
Rochelle explains: "I've had some people be supportive but then there's a lot of people who don't understand.
"They say things like 'you just need to calm down.'
"It's just not as simple as that - people don't understand how easy it is to lose control.
"When your mind is telling you a bad thing it feels horrible, it's not like going on a roller coaster and getting a thrill.
"It feels like the end of the world. You feel helpless," Rochelle says.
Dylan Kerr, who's counselling the Libertines, described anxiety as a "notoriously subtle and greatly prejudiced against" disorder.
This is something Rochelle can relate to.
"I've been called 'psycho' and 'mental' but I know I'm not, I just react differently to fears and phobias than other people.
"It's not something to be ashamed of.
"It's a lack of understanding - they don't know how to help you."
You can get support and help about anxiety and stress via BBC Advice.