Normal pressure hydrocephalus is a pathology causing dementia that is reversible. Despite the time elapsed since its discovery, its pathophysiology has not been clearly established and two theories have been proposed that try to explain the process, one based on changes in cerebrospinal fluid flow and the other on cerebral blood flow. In addition, the evaluation and diagnosis process is not determined, since there is no standard method and the symptoms are similar to other pathologies of the central nervous system, leading to the diagnosis as the summation of clinical symptoms and some findings in imaging which are not always constant.