What causes Parkinson’s disease?

Parkinson's disease results from the gradual degeneration of nerve cells in the portion of the midbrain that controls body movements. Therefore, people with Parkinson's disease may experience disorders in movements, postures, walking, and coordination and so on.
Parkinson's disease mostly affects older people but can even occur in younger adults. In early stage of the disease, signs are mild and barely noticeable -- a feeling of weakness or stiffness in one limb, or a fine trembling of one hand when it is at rest. However, as the disease progresses, the shaking worsens and spreads, muscles become stiffer, movements slow down, and balance and coordination deteriorate. Finally, depression, cognitive issues, and other mental or emotional problems are common for people with Parkinson's disease.
What Causes Parkinson’s disease?
Dopamine and acetylcholine are substances that are required by a portion of the brain called the basal ganglia, which regulate body movements. In people with Parkinson's disease, cells that produce dopamine begin to degenerate, throwing off the balance of these two neurotransmitters.
The cause that leads to the degeneration of the cells is still unknown.
• Genetic factor
Researchers believe that genetics sometimes plays a role in this cellular breakdown.
• Viral infection or exposure to environmental toxins
In rare instances, Parkinson's disease may be caused by a viral infection or by exposure to environmental toxins such as pesticides, carbon monoxide, or the metal manganese.
Parkinson's disease is a form of Parkinsonism, which is a more general term used to refer to the set of symptoms that is commonly associated with Parkinson's disease but sometimes stems from other causes. Other causes of Parkinsonism include:
• An side effect of prescription drugs
• Use of illegal drugs
• Exposure to environmental toxins
• Stroke
• Thyroid and parathyroid disorders
• Repeated head trauma
• Brain tumor
• An excess of fluid around the brain (called hydrocephalus)
• Brain inflammation (encephalitis) resulting from infection
Although there is no cure for Parkinson's disease, it is a treatable disease. Treatments for Parkinson's disease include medication, surgery, and other alternative and supportive treatments.