Jessica Thom, a sassy and smart 32-year-old from London, says the word "biscuit" 16,000 times a day. She also involuntarily bangs her head against the wall, beats her chest and when least expected, lets out a guttural sound or swears.
She describes her love-hate relationship with the disabling disorder Tourette syndrome in a new diary-style memoir -- "Welcome to Biscuit Land: A Year in the Life of Touretteshero," available in October.
In Britain, "biscuit" means "cookie," but Thom insists she is never really thinking about eating when she has her involuntary outbursts. Her brother-in-law recently took note of her verbal tic and counted her saying it 16 times a minute, or about 900 times an hour.
In one day alone, she has hit herself on the forehead with a phone, a carton of apple juice, a set of keys, a toilet roll and a strawberry.
Thom said that for years she viewed Tourette's as a liability, but now she sees it as a strength. Comparing herself to the film character Bridget Jones, who laughed at her quirks and foibles, Thom recounts hilarious, but also heartbreaking stories of her encounters with a world not used to her social outbursts.
"I know I tic all the time and it sort of pisses me off -- biscuit, biscuit," Thom told ABCNews.com. "But if I paid attention to it all the time, I wouldn't get much done. Sometimes with the Tourette's, I get overloaded -- biscuit, biscuit. I'll punch myself in the chest hundreds of times a day and my legs move erratically about."
"The challenges are dreadful, but it has helped make me a more resilient and empathetic person," she said. "You can overcome most things, and I have become more confident."
Tourette syndrome is a neurological disorder that is defined by multiple motor and vocal tics lasting for more than one year, according to the National Tourette Syndrome Foundation. The verbal tics can include grunting, throat clearing, shouting and barking.
It was named for a French neuropsychiatrist, Gilles de la Tourette, who assessed the disorder in the late 1800s. He did not have the disorder, so it is "Tourette," but colloquially, it's called "Tourette's."
The first symptoms, usually before the age of 18, are involuntary movements of the face, arms, limbs or trunk, such as kicking or stomping. They are frequent, repetitive and rapid. The patient cannot control these movements and they can involve the whole body.
Fewer than 10 percent of all patients swear or use socially inappropriate words.
Thom is "clearly an outlier," according to Dr. Jonathan Mink, chief of pediatric neurology at Rochester University, who sits on the board of the Tourette association. "She is atypical and at the extreme end of the spectrum."
"She is probably not thinking 'biscuit' all the time," said Mink, who does not treat Thom. "It's kind of an urge of need to do it. A lot of people say it's like an itch that needs to be scratched."
He estimates one in 100 children has some degree of Tourette syndrome, a disorder that is little understood and whose cause likely has a genetic link.
Many patients also have symptoms associated with attention deficit hyperactivity disorder and obsessive compulsive disorder.
"The majority of kids, even those bad enough to seek treatment, are likely to have their tics diminish or go away," said Mink.
Habit reversal therapy -- teaching a person with Tourette's to hold their breath, for example, instead of saying the repeated word, can sometimes help. Antidepressants are used to treat associated anxiety.
Thom, who has had tics since she was six, has used both therapies, but no avail.
"I tried instead of banging my chest to try to stretch my arm out, but it didn't work for me," she said.
Thom does take muscle relaxants but other medications have caused undesirable side effects.
She writes that the physical tics make her feel "a bit like suddenly being wrenched from the inside or as if someone's put itching powder in my blood."
Thom lives with a roommate, but she concedes there is still "quite a lot of risk." She recently fell in the shower and now uses a wheelchair.
The intensity of the disorder "fluctuates and changes," according to Thom. "Just when you think you got one thing set with your tics, something else comes up."