Inclusion Criteria:
* Healthy, as determined by medical history
* Group Specific Eligibility
* PTSD Group
* Lifetime PTSD: screened using Primary Care PTSD Screen for DSM-5 (PC-PTSD-5) and confirmed via Clinician Administered PTSD Scale for DSM-5 (CAPS-5)
* Prior trauma exposure: screened using Brief Trauma Questionnaire (BTQ)
* Self-report having repetitive nightmares contributing to disrupted sleep
* Poor overall sleep quality: PSQI score 6 or higher
* Control Group
* No lifetime PTSD: screened using PC-PTSD-5
* No prior trauma exposure: screened using BTQ
* Do not self-report having repetitive nightmares contributing to disturbed sleep
Exclusion Criteria:
* Pre-existing (e.g., diabetes, liver, kidney disease) or unstable medical condition (e.g., uncontrolled hypertension or active CVD or cancer) or systemic illness that would interfere with interpretation of the study outcomes
* Body Mass Index ≥ 40 kg/m2
* Use of medications that might influence cardiovascular or renal function (i.e., antihypertensive, lipid lowering medications, GLP-1/GIP RAs)
* Active infection (note, anyone with an active infection would become eligible once the infection has ended)
* Abnormal thyroid, liver, or kidney function testing during the screening examination or bloodwork. Abnormal kidney function defined as creatinine \>1.3mg/dL. Abnormal liver function tests within 1.5x ULN. UCH Clinical Lab ULN for AST and ALT are 39 and 52, respectively. Women with TSH levels outside of the normal range (0.5-5.0 mLU/L) will be referred to their PCP and will be allowed study entry once their TSH levels are normalized \> 3 months
* Plasma glucose \>126 mg/dl under fasting conditions
* Use of insulin or sulfonylureas
* Pregnant, within 12 months postpartum or currently breast feeding
* Current history of substance (excluding marijuana) or alcohol abuse per the SCID-5. Adults with past substance or alcohol use disorders will be allowed to participate.
* Report elevated acute risk for suicidal self-directed violence warranting immediate hospitalization (e.g., suicidal ideation with intent, evaluated by the C-SSRS).
* Shift workers
* Diagnosis of active disorder of arousal from non-rapid eye movement sleep, rapid eye movement sleep behavior disorder, or narcolepsy
* Nocturia that causes awakening from sleep
* Epworth Sleepiness Scale: Question #8 score above "0" will prompt an additional question: Do you drive ("get behind the wheel") when you are drowsy? The answer must be "No" to be enrolled in the study due to safety concerns
* Known sleep walking or acting out dreams (contraindication to NightWare use)
* Diagnosis or suspicion of dementia
* Participants experiencing severe cognitive impairment or current psychiatric symptoms of such severity that would preclude participation (e.g., active psychosis, imminently suicidal)
* Current use of vitamin/supplements (including melatonin) or anti-inflammatory medications, participants will be included if they are willing to stop taking vitamin/supplements or anti-inflammatory medications 2 weeks prior to the first vascular visit.
* Current or planned participation in an interventional study during the present study
* Participants must have access to wireless internet and two power outlets where they sleep
