The cause of Parkinson's disease is mainly due to a part of the brain called the brainstem, which has some black moles and clusters containing a large number of neurons that can produce dopamine. The death of these neurons in the substantia nigra of the midbrain, caused by various factors, leads to Parkinson's disease. This results in noticeable slowness of movement in the limbs, muscle rigidity, as well as tremors, and unstable walking and other clinical manifestations. The causes of the death of dopaminergic neurons in the substantia nigra include genetic factors. Additionally, age is the biggest cause of the disease. Furthermore, dysfunctions in mitochondrial function, ischemia and hypoxia in the midbrain, certain traumas, and the use of drugs that deplete dopamine can all potentially cause Parkinson's disease.