Doctors have found a 10-centimetre-long leech living in an impossible place - the windpipe of a 16-year-old boy.
Two months ago, Tao Jiayuan felt ill and his voice became hoarse. His mother thought he had caught a cold and gave him some medicine - it didn't work.
Gradually the boy lost weight and felt weak. It wasn't until he had difficulty breathing that his family took him to hospital.
Doctors found a leech living in his windpipe.
Nan'an Division of Yibin No. 2 Hospital, in Yibin City in southwest China's Sichuan province, performed an operation on the boy late last week and removed the leech. The bloodsucker seemed hardly affected by the dose of anaesthetic given to the boy and kept creeping on the white paper when it was out of the boy's throat.
Though it is an extreme case, it is possible for leeches to steal their way into the human body, according to Doctor Chen Bing who was in charge of the operation.
"Leeches may exist in human's nasal cavity or throat," Dr Chen said.
Leeches usually live in fresh water environments, such as creeks, rice fields and ponds.
"He must have drunk stream water when working in the field," said Tao Chuanhua, the boy's father.