A backpacker found a 3in (7.5cm) leech that had been living up her nose for a month after a trip to South East Asia.
Daniela Liverani, 24, from Edinburgh, had been having nosebleeds for weeks but put them down to a burst blood vessel from a motorbike crash.
Ms Liverani was having a shower last Thursday when she was realised the dark shape wriggling in her nose was actually an animal.
Hospital staff used forceps and tweezers to remove the parasite.
Ms Liverani believes she picked up the leech in Vietnam or Cambodia, but even when she felt it moving up and down her nostril, she thought it was a blood clot.
She told BBC Radio Scotland: "Your initial reaction isn't to start thinking, oh God, there's obviously a leech in my face."
It was when Ms Liverani was in the shower that the leech's presence was most noticeable.
She said: "Obviously my nasal passages would open up because of the steam and the heat and the water, and it would come out quite far, about as far as my lip.
"So I could kind of see it out of the corner of my eye but still didn't think it was a worm because it just looked like a blood clot.
"On Thursday I jumped out the shower and I unsteamed the mirror and I had a proper good look, and I could see little ridges on him."
That was the moment when Ms Liverani realised she was housing a parasite.
She went to accident and emergency where doctors removed "Mr Curly" - as Ms Liverani nicknamed the leech - with forceps and tweezers.
"The doctors did a great job, hats off to them, because obviously they don't see something like that every day", she added.
"They did what they could in a strange situation while trying to keep their cool."
Ms Liverani then took the leech home for the night, at the doctors' suggestion. However, Mr Curly did not live to see another day.
"He's in an Edinburgh City Council bin," said Ms Liverani. "He's probably long gone by now. I boiled him first."