A patient may not develop these difficulties, but over time, up to 60 percent of patients suffer from more than one nonmotor symptom. Many are treatable with standard therapies.

Cognitive and behavioral problems:

• Depression
  
• Apathy
  
• Fatigue
  
• Dementia
  
• Anxiety
  
• Sleep disorders
  
• Difficulty with impulse control
  
• Sensory difficulties
• Loss of sense of smell
  
• Pain in a limb affected by muscle stiffness
  

Problems with bodily functions

• Drooling
  
• Fainting or dizziness after standing up, due to abnormalities in blood pressure regulation
  
• Sexual dysfunction
  
• Constipation
  
• Frequent urination or incontinence
  
• Skin problems, such as eczema or excessive sweating