Idiopathic Parkinson’s disease (IPD) is the most common neurodegenerative disorder after Alzheimer’s disease. The major motor symptoms of IPD are resting tremor, bradykinesia, rigidity, and postural reflex disturbance. Apart from these dopaminergic motor symptoms, non-motor symptoms also develop secondary to serotonergic, noradrenergic, cholinergic, and autonomic nervous system involvement, including major neuropsychiatric symptoms, autonomous disorders, sleep disorders, and sensory symptoms. Non-motor symptoms are seen in about 90% of IPD patients in all stages of the disease. However, these symptoms are usually not recognized and are underestimated when planning therapeutic strategies.