Parkinson's Disease (MedlinePlus)
Parkinson's disease (PD) is a type of movement disorder. It happens when nerve cells in the brain don't produce enough of a brain chemical called dopamine. Sometimes it is genetic, but most cases do not seem to run in families. Exposure to chemicals in the environment might play a role.
Symptoms begin gradually, often on one side of the body. Later they affect both sides.
Health Topic Category