 -- For 12-year-old Katelyn Thornley, the sound of sneezing has become painfully familiar.

Three weeks ago, she began sneezing and hasn’t stopped.

“I was walking out of a clarinet lesson and all of a sudden it kind of started like little spurts,” the seventh grader from Angleton, Texas, told ABC News. “It was just a few sneezes here and there, but by the time I went to bed, I had sneezed 30 times that night.”

Katelyn averages at least two sneezes a minute, according to her doctor, and has episodes which can cause her to sneeze 20 times per minute, for 15 minutes at a time. Sleeping is the only way she has been able to find relief.

“I can control it sometimes, but it’s really painful,” she explained.

And so far, doctors at Texas Children’s Hospital in Houston haven’t been able to figure out exactly what is causing the uncontrollable sneezing, referring to the condition as a “tic.”

“She had kind of a funny feeling that she described in her nose and that piece of her history is very common for tics,” Dr. Mered Parnes, child neurologist and director of the pediatric movement disorders clinic at Texas Children's Hospital, said.

It’s not the first time doctors have seen cases like this. In fact, some believe tics may be triggered in the brain by something stressing the child out. About 10 percent of all kids are affected by tics.

“She can’t really go to school or do anything normal,” said Katelyn’s mom, Erika Hodges. “She can’t eat well, she has to sip. She can’t drink. It’s affected everything.”

“She had an episode ... where it was 45 straight minutes,” her father Travis Thornley said fighting back tears. “She was screaming in pain a couple of time and all I can do is just hold her tight and wait for her to go to sleep.”

And Katelyn just wants to get back to seventh grade.

“This has taken a huge toll on my life,” she said. “I want nothing more than for this to end. I just want it to be gone for good.”