KNOXVILLE, Tenn. — Gracie Brown is a healthy 10-year-old. She plays softball and starts fifth-grade in the fall. But on Sunday, she was just getting ready for church with her sister when something strange happened. 

"I think I maybe got five curls in and she looked like she was a little woozy," her sister Alicia Phillips said. 

Phillips thought Gracie was going to vomit, but then she got pale, clammy and started to sweat. 

"Her pupils went all the way maximum to her eye color. Scared me to death," Phillips said she screamed. 

Gracie passed out. 

"I could like squint and kind of see them, kind of," she said. 

She said she could still hear, but was limp in her sister's arms. 

"If I had been by myself I would've called 911 immediately. I thought she was dying in my arms," Phillips said.  

They called a doctor, rushed to the ER, did the tests and awaited the diagnosis: It was 'hair grooming syncope.' 

"And at this point, I'm like 'What?' I've never heard of anything like this before. I kind of thought he was joking at first," Phillips said. 

It may sound made up, but doctors said it's real. 

"Syncope is basically passing out, and hair grooming is known to be a precipitant of that," pediatrician Dr. Kurt Brandt said.  

He said fainting like Gracie did isn't uncommon, and hair grooming -- cuts, blow drys, curling, etc -- can cause it. 

"It may be the pulling of the hair, possibly pain, possibly stimulation of the scalp," he said. "Your blood pressure goes down and you pass out."

"This is not dangerous," Phillips said doctors told her. "They just faint and they come back and they're fine."

But she said she's not risking it again. 

"I will never touch her hair. I won't put it in a ponytail, I won't brush it, I won't curl it, I won't do anything."