Patients suffering from Parkinson's disease show signs and symptoms of damage to the various parts of the nervous system. Parkinson's disease shouldn't be considered only in the context of its motor disorders, but should be considered by its, no less important, non - motor symptoms, which still further add to the already significantly disrupted life quality. The clinical diagnosis of Parkinson's disease is usually based on criteria set by the UK Parkinson's Disease Society Brain Bank. There must be present at least 2 or 3 of motor symptoms, so that the existence of Parkinson's disease can be firmly confirmed. However, these criteria are not sufficient enough to distinguish Parkinson's disease from other forms of parkinsonism, nor do they contemplate the non - motor symptoms. The most common non - motor symptoms of Parkinson's disease (psychiatric disorders, dementia, sleep disorders, autonomic disorders) are often unrecognized and therefore untreated. It is important to know that non - motor symptoms usually have similar etiology as motor symptoms. When one symptom is well treated, we can often see an improvement in another symptoms. One must also take into account that the treatment of the symptoms of one type can cause deterioration of the underlying disease. Therefore, the treatment of Parkinson's disease should be multidisciplinary. Despite the instense research, there is still no good enough available therapy to prevent the onset of Parkinson's disease, or to stop its progression.