The process of PD in your body may start 5 to 20 years before the first symptoms are recognized. In those rare cases of inherited PD, the process may even start at birth. The long period between the onset of the process of PD and the appearance of symptoms makes it difficult to distinguish those factors that may have caused the disease from those factors that may have sped up a disease that was incubating.
The following factors are associated with an increased risk of developing PD. It’s not known if each of these factors is a direct cause of PD or if it’s an indirect cause that increases the susceptibility to developing PD:
- People 60 years or older
- People who have a family member with PD
- People exposed to toxic chemicals (the degree and duration of exposure are important, but are usually not known or documented)
- People who continuously and habitually use amphetamines, cocaine, heroin, and methamphetamine
- People who had encephalitis (a viral infection of the brain)
- People who had a significant brain injury
- People with Gaucher’s disease (there is a link between the genetics of PD and the genetics of Gaucher’s disease)