Parkinson's disease affects the way you move. It happens when there is a problem with certain nerve cells in the brain.
Normally, these 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 many years. And there are good treatments that can help you live a full life.
No one knows for sure what makes these nerve cells break down. But scientists are doing a lot of research to look for the answer. They are studying many possible causes, including aging and poisons in the environment.
Abnormal genes seem to lead to Parkinson's disease in some people. But so far, there is not enough proof to show that it is always inherited.
The four main symptoms of Parkinson's are:
- Tremor, which means shaking or trembling. Tremor may affect your hands, arms, or legs.
- Stiff muscles.
- Slow movement.
- Problems with balance or walking.
Tremor may be the first symptom you notice. It's one of the most common signs of the disease, although not everyone has it.
More importantly, not everyone with a tremor has Parkinson's disease.
Tremor often starts in just one arm or leg or on only one side of the body. It may be worse when you are awake but not moving the affected arm or leg. It may get better when you move the limb or you are asleep.
In time, Parkinson's affects muscles all through your body, so it can lead to problems like trouble swallowing or constipation.
In the later stages of the disease, a person with Parkinson's may have a fixed or blank expression, trouble speaking, and other problems. Some people also lose mental skills (dementia).
People usually start to have symptoms between the ages of 50 and 60. But sometimes symptoms start earlier.