Parkinson's disease occurs when there is a problem with certain nerve cells in the brain. The disease affects the way you move.
Normally, these types of nerve cells make an important chemical called dopamine. Dopamine sends signals to the part of your brain that controls movement. It lets your muscles move smoothly and do what you want them to do. When you have Parkinson’s, these nerve cells break down. Then you no longer have enough dopamine, and you have trouble moving the way you want to.
Parkinson’s is progressive, which means it gets worse over time. But usually this happens slowly, over a period of many years. And there are good treatments that can help you live a full life.