"This test has the potential to massively improve the diagnosis and management of people with Parkinson's disease," says neurologist Monty Silverdale from the University of Manchester in the UK.

After noticing her husband developing a more musky odor many years before he was officially diagnosed with Parkinson's, it was discovered that Milne could smell the signs of the disease on people.

"When we do this, we find more than 4,000 unique compounds of which 500 are different between people with Parkinson's disease compared to the control participants," says chemist Depanjan Sarkar from the University of Manchester.