A Scottish woman claimed her husband’s smell changed subtly before he was diagnosed with Parkinson’s disease. When researchers conducted tests with the woman, they found she was able to identify people living with Parkinson’s from people without the condition by smelling skin swabs taken from both groups. Now scientists have identified the 10 molecules which appear in high concentration of the skin swabs from Parkinson’s patient. The astounding discovery is helping scientists develop the first diagnostic test for the disease.