Nicole Delien, 17, from Pennsylvania said she's missed out on Thanksgiving, Christmas, birthdays and even the first family trip to Disney World.
Her mom, Vicki, said Nicole will sleep 18 or 19 hours a day, and when she does wake up to eat, she said Nicole is in a sleepwalking state which she doesn't remember.
Vicki Delien said it was very frustrating just getting a diagnosis, CBS Radio reported.
They went to various hospitals until a doctor at Allegheny General Hospital finally realised that she was suffering from the rare sleeping disorder Kleine-Levin.
"Affected individuals may go for a period of weeks, months or even years without experiencing any symptoms, and then they reappear with little warning," the Kleine Levin Syndrome Foundation website stated.
In addition to excessive sleeping, symptoms include disorientation, hallucination, child-like behaviour, binge-eating and periods of hyper-sexuality when awake, according to an Oxford Journals report.
More From This Section
That report said the disorder predominately affects young males.
The cause of Kleine-Levin Syndrome is unknown, both medical sources indicate.
Medication helps spread the sleeping episodes further apart for Nicole. The last one was in March, but Nicole said she's scared of when it will happen again.
The family recently went on a national talk show because they want other families to know about the rare disorder.