Parkinson's is a progressive neurological condition.
People with Parkinson's don't have enough of a chemical called dopamine because some nerve cells in their brain have died.
Once I accepted myself as a person with Parkinson's, and did not think of myself as a lesser person because of this, other people did the same. It is not the most important thing about me.
Caroline, diagnosed in 2003
Without dopamine people can find that their movements become slower so it takes longer to do things.
The loss of nerve cells in the brain causes the symptoms of Parkinson's to appear.
There's currently no cure for Parkinson's and we don't yet know why people get the condition.
Parkinson's doesn't directly cause people to die, but symptoms do get worse over time.
One person in every 500 has Parkinson's. That's about 127,000 people in the UK.
Most people who get Parkinson's are aged 50 or over but younger people can get it too.
Everyone with Parkinson's has different symptoms.
The main symptoms of Parkinson's are tremor, rigidity and slowness of movement.
As well as affecting movement, people with Parkinson's can find that other issues, such as tiredness, pain, depression and constipation, can have an impact on their day-to-day lives.
Symptoms and the speed at which the condition develops will differ from one person to the next.
Find out more about all Parkinson's symptoms.
As Parkinson's progresses, an increased amount of care and support may be required, although many people maintain a good quality of life with limited care or treatment.
We fund research into finding better treatments and ways to improve the quality of life for people with Parkinson's as well as finding a cure.
The Parkinson's nurse was immensely helpful – coming to my house when I was newly diagnosed and explaining Parkinson's to me so well.
Diana, diagnosed in 2004
It's not easy to diagnose Parkinson's. There are no laboratory tests so it's important that the diagnosis is made by a specialist.
The specialist will examine the person for any physical signs of Parkinson's and take a detailed history of the symptoms they're experiencing.
Find out more in our Diagnosing Parkinson's information sheet.
There are guidelines for the diagnosis of Parkinson's which health professionals should follow:
Everyone's experience of Parkinson's is different.
We have a lot of information for people with Parkinson's, their family, friends and carers on topics relating to everyday life with Parkinson's.