Longhauler's Cohort -  Inclusion Criteria:  Ability to give informed consent or LAR. At least 18 years old. Ability of subject or LAR to read and speak the English language. Positive PCR or antibody test within 12 months of initial study visit. Patient of the Long-Hauler Syndrome clinic and differential diagnosis of Long-Hauler Syndrome.  Exclusion Criteria:  Any potential participant who refuses medical record review. Pregnant females. Incarcerated individuals. Inability to cooperate or any medical condition that, in the opinion of the investigator, interferes with the evaluation of the study objectives or increases the subject's risk by participating in the study.  Control Cohort -  Inclusion Criteria:  Ability to give informed consent At least 18 years old Ability of subject to read and speak the English language  Exclusion Criteria:  Known case of COVID-19. Any potential participant who refuses medical record review. Pregnant females. Incarcerated individuals. Inability to cooperate or any medical condition that interferes with the evaluation of the study objectives or increases the subject's risk by participating in the study.  COVID-19 Control Cohort  Inclusion Criteria:  Ability to give informed consent. At least 18 years old. Ability of subject to read and speak the English language. Known case of COVID-19.  Exclusion Criteria:  Known Longhauler's syndrome/Post-COVID Any potential participant who refuses medical record review. Pregnant females. Incarcerated individuals. Inability to cooperate or any medical condition that interferes with the evaluation of the study objectives or increases the subject's risk by participating in the study.