Intravenous (IV) Saline and Exercise in Postural Tachycardia Syndrome (POTS)

Inclusion Criteria: * Meet diagnostic criteria of Postural Tachycardia Syndrome (POTS) 28 * Age between 18-65 years * Male and female are eligible (although the majority of POTS patients are female). * Able and willing to provide informed consent Exclusion Criteria: * Presence of medical conditions that can explain postural tachycardia (e.g., acute dehydration, medications) * Pregnancy * Other factors which in the investigator's opinion would prevent the subject from completing the protocol. * Patients who are bedridden or chair-ridden