Primary dysautonomias, also known as primary autonomic disorders, refer to a group of conditions that affect the autonomic nervous system (ANS) without any identifiable underlying cause, such as degenerative diseases, autoimmune disorders, or physical injuries. The ANS is responsible for regulating essential functions like heart rate, blood pressure, digestion, and body temperature, and its dysfunction can lead to a variety of symptoms, including dizziness, fainting, rapid heartbeat, and gastrointestinal disturbances. Examples of primary dysautonomias include pure autonomic failure, multiple system atrophy, and familial dysautonomia.