Like most children her age, Jennifer Lloyd loves watching her favorite shows on TV.
But when a scary bit is about to happen the ten-year-old has to leave the room quickly - because the sudden shock could kill her.
Jennifer is one of just six known sufferers of polyglandular Addison's disease, which causes her to become ill whenever she is surprised or shocked.
The condition means she is unable to produce adrenaline in response to alarm or any sudden form of emotional or physical stress.
Instead her body goes into shock and her organs could shut down unless she receives medical treatment.
It means Jennifer can only watch television with the permission of her parents, who also watch with her then ensure she leaves the room if they fear something startling is about to happen.
Since Jennifer was diagnosed three years ago, her parents Amanda, a nurse, and Robert Lloyd, 47, an engineer, of Prestwich, Greater Manchester, have been desperate for more information on the disease.
Named after Dr Thomas Addison, who first described it in 1855, the condition affected U.S. president John F Kennedy.
The polyglandular form of the disease is far rarer than the ordinary one.
The inability to produce adrenaline has a knock-on effect on blood pressure, major organ function and salt levels.
Jennifer suffers from stomach and kidney problems as a result of the condition and has to take a complex range of medication to help her body cope.
Her parents also carry an emergency kit to provide extra medication-when required.
Mrs Lloyd, 44, said: "When anything particularly good or bad happens, we have to handle it very carefully so it doesn't surprise Jenny.
"We always have to expect the unexpected."