A woman complaining of a sore throat stunned doctors who found a three-inch leech lodged in her windpipe.

The woman, named Wei, 60, from a village near Wenshan, in south-western China's Yunnan Province, had been coughing up blood for half a month before she decided to seek medical attention on September 17.

She went to the Wenshan Prefecture Traditional Chinese Medicine Hospital for treatment and said she was suffering from a painful cough followed by a foreign body sensation in her throat.

A CT scan revealed there was indeed something stuck in her trachea. However, doctors had to perform a delicate bronchoscopy to get a better look at the shadowy figure that appeared on the scans.

During the procedure, they were shocked to find a three-inch leech near her vocal cords. The blood-sucking creature that has suction cups on its body that help it maintain a tight grip was stuck to her tracheal wall.

A surgical team guided by Dr Zhao Xiao carefully extracted the live parasite, with video footage showing astonished staff looking at its moments after it was removed.

Dr Li Xianrong, the director of the Pulmonology Department, said that the patient had been working in the mountains before falling ill. She had drunk untreated water from mountain streams, which probably introduced the leech into her body.

Surgeons believe that after Wei swallowed the parasite, it had crawled up to her trachea and remained there for two weeks while feeding on her blood.

They added that her case is not entirely uncommon, and the primary cause is almost always drinking untreated water.

Wei's symptoms reportedly disappeared immediately after the leech was removed. She quickly returned to normal, was in good spirits, and was able to leave the hospital the next day, local media reported.