Joy Milne is a 71-year-old Scottish woman living in Perth, Scotland. When she was in high school, she danced with a swimmer who was one year older than her, Les. Les entranced her. Joy was sensitive to smells, and one of the things she loved about Les was his scent.

A few years later, Joy and Les were married. He had become a doctor, and she was a nurse. They had three kids and were totally in love. Life was good.

One day, Les came home from a day of work at the hospital. He was 31. Joy immediately noticed that there was something different about the way he smelled. She sent him to have a shower, but the smell remained.

Over the next few years, the smell gradually worsened. No matter how frequently Les bathed, the scent wouldn’t go away. Soon Joy began to notice other changes, particularly in the way he behaved.

When Les was 45, Joy decided to take him to a neurologist. They received a diagnosis that he had Parkinson’s disease.

Joy and Les struggled with the diagnosis alone for some time until they decided to join a Parkinson’s support group.

One day, they went to meet the group for the first time. They were a bit late arriving, so arrived to a room full of people. When Joy walked in, the first thing she noticed was the smell—the same smell she’d smelled on her husband. Joy couldn’t smell the scent on the carers, only on the people who had been diagnosed with Parkinson’s.

When they arrived home later that day, Joy spoke to Les about what she’d experienced. He was astonished. It was the start of a new field of medicine, linking smells to diseases.