Parkinson's disease happens when there is a problem with certain nerve cells in the brain that control movement. The classic symptoms are shaking (tremor), stiff muscles (rigidity), and slow movement (bradykinesia). It may also cause problems with balance or walking, as well as confusion and memory loss.
Parkinson's gets worse over time. But usually this happens slowly, over many years.
Medical Review:Anne C. Poinier, MD - Internal Medicine & Adam Husney, MD - Family Medicine & Martin J. Gabica, MD - Family Medicine & G. Frederick Wooten Jr., MD - Neurology