Dementias are a group of neurological disorders that often affect memory, thinking ability, and behavior. This term can be used to describe various conditions, including Alzheimer's disease, Huntington's disease, Parkinson's disease, and Creutzfeldt-Jakob disease. There are several synonyms that can be used to describe this group of disorders, such as cognitive impairment, neurodegeneration, senility, cognitive decline, brain damage, and memory loss. Each synonym highlights a different aspect of the disease, but all are used to describe the same overarching condition. Although there are treatments available for some types of dementia, there is currently no cure for any of the dementias, making it a significant public health concern.