Hayley Lairmore's mystery illness began on her 14th birthday last year when she threw up after a fun-filled day at Disney World. For nine months as it went undiagnosed, she dropped out of school, disengaged from life and dwindled to 70 pounds.
"At first we thought maybe it was too much junk food or possibly the flu, but the throwing up continued," said her mother, Christine Lairmore of Arrowhead Lake, California. "If she tried to eat, it came right back up.
At its worst, the high-achieving girl who played soccer and loved class was tormented by abdominal pain and vomiting, up to a dozen times a day, crying to her mother for help.
"Every night at 2, 3, 4 in the morning, we'd be up," said Lairmore, 43. "The nights were horrible. We would watch movie after movie and she was in excruciating pain. She would cry, 'Mommy, you have to help me, please help me,' but no one could help."
Lairmore and her husband Robert, an engineer who designs Louisville Slugger bats, were powerless to help their daughter. Every doctor and specialist -- even at the top medical centers around Los Angeles -- told them it was all in Hayley's head. One recommended a psychiatrist.
"I got this all the time: 'She's doing it on purpose.' 'She needs therapy,'" said Lairmore. "And I got told more times than I want to hear ever again, 'She's doing it for attention.'"
One gastroenterologist wrongly diagnosed constipation and prescribed laxatives so strong that Hayley had to wear a diaper to make the 30-minute drive from their mountain home to the doctor.
"We had to buy her todder pull-ups -- and she was so emaciated, she could fit into them," said Lairmore. "Imagine the horror, sitting next to her 11-year-old brother in the car."
After seven months, ruling out food allergies, celiac disease and eating disorders, the doctors threw up their hands.
But Lairmore didn't. She was desperate for answers and spent hours on the Internet, even though she laughs that she is not computer-savvy.
"I am not woman easily dismissed by a doctor," she said.
Late one night, in what she calls a "fluke," Lairmore stumbled across a chat room where a teenage girl was talking about a strange-sounding condition called POTS..
Curious, she followed more links until they led to a YouTube video of a girl talking about symptoms that sounded familiar.
"As soon as I clicked on it, you could almost hear the music and the bright lights," said Lairmore. "It was one of those surreal moments and I felt electricity through my body. You are talking about my daughter."
That, in turn, led her to another YouTube video of Dr. Phil Fischer, the Mayo Clinic's own "House" -- a kinder, gentler version of the TV character -- who diagnoses complex pediatric illnesses.
Lairmore said she called the Mayo Clinic and the receptionist told her, "You sound exactly like the moms we hear from every day."
"I literally started crying," she said.
POTS, or postural orthostatic tachycardia syndrome, is a disorder of the autonomic nervous system -- the master regulator of heart rate, blood pressure, respiration and other vital functions.
Its classic symptoms are dizziness and a rapidly increased heart rate when getting to one's feet, because the body cannot adapt to gravity.