Leigh Simons, 18, suffers with a severe manifestation of the phobia, emetophobia, after she was vomited on at nursery school.
Now, in her first year as a psychology student at the University of Bath, Leigh fears she may never fully eradicate her fear, but is managing to live with the condition, which is thought to affect around one in 20 people in the UK.
She said: “We had a party at nursery school – I was around three or four – and my friend was stuffing her face with fairy cakes when she threw up all over my dress.
“That is literally my earliest memory.
“What made it so much worse was the reaction of my teacher, who just panicked.
“I’m studying psychology now and kind of realised that that was where it all started.”
Leigh says her early life was ridden with anxiety about people being in her house, about getting sick and eating dodgy school dinners.
Speaking to student newspaper The Tab, she said: “I don’t ever remember not being terrified of sick. If anyone was in the house, I’d have a panic-attack.
“I couldn’t leave the house. I would just lock myself in my bedroom.
“But I still went to school. I didn’t have any extended period of absence from school.
“I tried not to think about it. I thought I could just deal with it on my own.
“I didn’t think of it a clinical condition – I just thought I was a bit different.”
But Leigh, originally from Birmingham, says she started seeing a therapist when she was 15 and started trying to tackle the problem head-on.
She said: “We tried cognitive behavioural therapy, exposure therapy – my therapist didn’t really know what to do because it was quite unusual in that I was still functioning.
“The exposure therapy was quite weird; we would go though pictures of vomit. Initially it was just looking at pictures of cartoon characters being sick, because I couldn’t look at real pictures.
“It was so bad at one stage that I couldn’t watch episodes of the Simpsons where people were gagging, for example.
“But after a while, it did help. I can watch more or less anything on TV now.”
When she applied to uni, Leigh said the idea of moving away, into a new environment was almost unbearable.
She said: “At first it was quite hard being around so much alcohol and I could be quite controlling about what people could and could not drink around me.
“I do drink myself, but I’m really careful. I never, ever drink to the point of wanting to throw up.
“I have to check all my food and I’m really picky about what restaurants I eat in, making sure they have a five-star food-safety rating.
“I never stop for a kebab on the way home from a night out.
“My friends at uni are all really nice about it, and don’t laugh about it too much. One night, I stayed in and one of my friends cam home early because she was sick.
“I was asked if I could look after her because she might be sick, and I just basically just said, ‘no, sorry. I can’t’. I felt really bad about it, and they did understand in the end.”
Leigh says she want to go one to do a PhD in clinical psychology, but insists it has absolutely nothing to do with her condition.
She said: “I just really love doing it.