Emily, from Stapleford in Nottinghamshire, has a neurological disorder that means she could suddenly pass out at any time.
It started when she was 12-years-old and the episodes sometimes lead to loss of sight, speech or being able to walk.
The condition resulted in Emily barely being able to leave her house and she had to drop out of school.
Five years ago Emily got a puppy, Barna - and her new wet-nosed friend turned her life around.
One day, when Barna was just 6-months-old, something extraordinary happened as Emily was having dinner with her grandparents.
Emily explains: "Out of nowhere he comes sprinting into the kitchen and sat down directly in front of me and gave me this really intense stare and a single bark."
For a dog that rarely barked, Emily found this strange. Five minutes later she was unconscious.
At first she put it down to coincidence, that her dog had detected she was about to pass out, but then it happened again and again.
Barna's incredible sense of smell detects when Emily is about to have an attack, 5 minutes before it happens, allowing her to move to somewhere safe.
His nose can sense changes in Emily's pheromones - The equivalent of smelling a spoonful of sugar in two Olympic-sized swimming pools.
Barna once alerted Emily about an attack when she was in the bath and she says if he hadn't been there then she would have drowned.
His unusual, life-saving, ability has now been recognised by the charity Medical Detection Dogs.
Emily says she wouldn't be here today if she didn't have Barna by her side.