The 65-year-old South Korean woman had previously been diagnosed with osteoarthritis, a condition in which the cartilage and bones within the joints degrade, causing pain and stiffness, Fox News reports. But when pain relievers and anti-inflammatory drugs didn't alleviate the pain in her knees and only caused stomach discomfort, she had turned to acupuncture, the doctors wrote last week in the New England Journal of Medicine.

Acupuncture is an alternative medical practice that uses needles to purportedly stimulate certain points on the body, to alleviate pain or to treat various diseases.

In the woman's acupuncture treatment, the needles, which were presumably made of gold, were intentionally left in her tissue for continued stimulation, according to the report. 

However, leaving the needles, or any objects, in the body may not be such a good idea, said Dr. Ali Guermazi, a professor of radiology at Boston University, who wasn't involved with the case. Foreign objects left inside the body can lead to inflammation, abscesses and infection.

"The human body wants to get rid of the foreign object," Guermazi said. "It starts with some mechanism of defense, for example inflammation and forming [fibrous tissue] around the object."

Needles left in the body can cause other challenges, too. "The patient can't go into an MRI because needles left in the body may move, and damage an artery," Guermazi said.