Parkinson's disease is a problem with certain nerve cells in the brain that control movement. The main symptoms are shaking (tremor), stiff muscles (rigidity), and slow movement (bradykinesia). It may also cause problems with balance or walking. Other symptoms may include confusion, memory loss, pain, depression, sleep problems, trouble with speech and swallowing, and constipation.

Parkinson's gets worse over time. But usually this happens slowly, over years.