Overview

Parkinson’s disease is a progressive disorder that affects the nervous system and body parts controlled by the nerves. Symptoms start slowly. The first symptom may be a barely noticeable tremor in just one hand. Tremors are common, but the disorder may also cause stiffness or slowing of movement.

Symptoms

Parkinson’s signs and symptoms may include:

• Tremor. A tremor, or rhythmic shaking, usually begins in a limb, often your hand or fingers. The shaking may decrease when you are performing tasks.
• Slowed movement (bradykinesia). Over time, Parkinson’s disease may slow your movement, making simple tasks difficult and time-consuming. 
• Rigid muscles. Muscle stiffness may occur in any part of your body. The stiff muscles can be painful and limit your range of motion.
• Impaired posture and balance. Your posture may become stooped. Or you may fall or have balance problems as a result of Parkinson’s disease.
• Loss of automatic movements. You may have a decreased ability to perform unconscious movements, including blinking, smiling or swinging your arms when you walk.
• Speech changes. You may speak softly, quickly, slur or hesitate before talking. Your speech may be more of a monotone rather than have the usual speech patterns.

Causes

The cause of Parkinson’s disease is unknown, but several factors appear to play a role, including:

• Genes. Researchers have identified specific genetic changes that can cause Parkinson’s disease. But these are uncommon except in rare cases with many family members affected by Parkinson’s disease.
  However, certain gene variations appear to increase the risk of Parkinson’s disease but with a relatively small risk of Parkinson’s disease for each of these genetic markers.
• Environmental triggers. Exposure to certain toxins or environmental factors may increase the risk of later Parkinson’s disease, but the risk is small.

Risk factors

Risk factors for Parkinson’s disease include:

• Age. Young adults rarely experience Parkinson’s disease. It ordinarily begins in middle or late life, and the risk increases with age. People usually develop the disease around age 60 or older. 
• Heredity. Having a close relative with Parkinson’s disease increases the chances that you’ll develop the disease. However, your risks are still small unless you have many relatives in your family with Parkinson’s disease.
• Sex. Men are more likely to develop Parkinson’s disease than women.
• Exposure to toxins. Ongoing exposure to herbicides and pesticides may slightly increase your risk of Parkinson’s disease.

For more information, visit https://www.mayoclinic.org/diseases-conditions/parkinsons-disease/symptoms-causes/syc-20376055