Since the spring of 2020, a state of emergency has been declared due to the spread of the COVID-19 epidemic. Many patients visited the pediatric outpatient department due to social anxiety and indefinite complaints. Many patients have a temporary psychogenic reaction associated with anxiety. However, clinically, it is important to distin-guish it from orthostatic dysregulation（OD）. At our hospital, we are conducting a Schellong test using an electrocardiogram and an blood pressure monitor to diagnose OD. We retrospectively diagnosed OD and classified subtypes based on medical records of patients who visited our hospital with indefinite complaints and underwent the Schel-long test. The survey period was 13 months from January 2020 to the end of January 2021, and a total of 42 Schel-long tests were conducted on 40 patients. The mean age of the patients was 13.1 years, 22 boys and 18 girls, with a mean BMI of 19.1. The tests were performed in 29 cases in the morning and 11 cases in the afternoon. The main complaints based on the physical symptom items of the Pediatric Orthostatic Regulation Diagnosis and Treatment Guideline 2015 were headache in 23 cases, dizziness in 12 cases, late morning or absenteeism in 11cases, and diges-tive symptom in 10 cases. Loss of consciousness was observed in 13 cases. The Schellong test was positive in 36 of 40 cases. Postural tachycardia syndrome（POTS） accounted for 23 cases of OD subtype in Schellong test positive subjects. The severity was severe in 13 cases. In children with indefinite complaints, it is important to con-duct the Shellong test with the possibility of POTS in mind.
