A charity is looking for 3,000 Parkinson's sufferers to take part in the biggest ever study into the cause of the disease.
Parkinson's UK is investing more than £1.6 million in the Tracking Parkinson's research to learn more about the illness and improve chances of finding a cure.
The charity needs both people who have been diagnosed within the last three years and those aged under 50 when they were diagnosed.
The research, timed to coincide with the star of Parkinson's Awareness Week, will be led by Dr Donald Grosset from the University of Glasgow and will eventually link to around 50 centres around the UK.
The study hopes to identify elusive biomarkers for Parkinson's, such as signpost indicators in the blood. These could then help develop simple tests for diagnosis.
An early diagnosis is crucial if doctors are to be able to prescribe the right drugs for people with Parkinson's to control and, one day, cure the illness, Parkinson's UK said.
Symptoms of the illness include tremors, movement problems, anxiety, memory lapses and digestion problems. Such symptoms will be closely monitored for up to five years as part of the study.
Dr Kieran Breen, director of research and innovation at Parkinson's UK, said: "Studies like Tracking Parkinson's could make a huge difference and help us to ultimately find a cure.
"Identifying biomarkers is key and would revolutionise the diagnosis and management of Parkinson's. Finding a cure for Parkinson's is like building a gigantic jigsaw, but we still have a number of the pieces missing. This vital new study will help us fill in some of the gaps in our knowledge.
"We hope Tracking Parkinson's will also help us to identify people who have a greater 'risk' of developing Parkinson's and we can monitor them more accurately."
Dr Grosset said: "The cure for Parkinson's is a global challenge and all the samples gathered from our thousands of volunteers will be available for analysis by researchers the world over.
"This, in itself, will speed up our ultimate goal - to develop a cure for Parkinson's.
"I am very excited to be leading this cutting-edge research collaborating with top researchers from Scotland, England, Wales and Northern Ireland."