It took the man's doctors a week to find out that their patient was taking these pills, and that his symptoms were signs of lead poisoning. (In developed countries, lead poisoning is rare because lead levels in the environment are controlled.)

"It was a very difficult case. The patient had unspecific symptoms, such as abdominal pain, confusion, constipation, vomiting," said Dr. Omar Kherad, a physician at the Hôpital de la Tour in Geneva.

"We did all the normal tests — in this case, gastroscopy, CT scan, all the blood tests," Kherad said. "We did not find anything, initially."

The doctors finally asked the patient whether he was taking any traditional remedies, because although he lived in Switzerland, he frequently traveled to Bhutan, where people often use alternative medicine.