Sympathetic Activity in Post-injury Outcomes: Impact on Sleep and caRdiovascular Health InvesTigation

The goal of this observational study is to learn about the long-term health of United States military service members who were injured during combat. The main questions it aims to examine are: * How does the severity of a combat injury impact 1) cardiovascular risk, 2) the sympathetic nervous system and arrhythmias, 3) blood pressure, and 4) sleep disorders? * Are self-reported mental health symptoms related to sympathetic nervous system hyperactivity, sleep disorders, and cardiovascular risk in combat-injured service members? This study will recruit from a sample of participants in another research study called the Wounded Warrior Recovery Project (WWRP) who 1) agreed to be contacted about future research studies and 2) have a record of a combat injury within the Injury Severity Score ranges required for this study. Participants will: * Provide demographic information and a medical history review * Visit a local laboratory for biometrics measurements and to provide blood and urine samples * Wear an ambulatory electrocardiogram monitor for 24 hours per day for seven consecutive days * Wear a home sleep test monitoring device for one night * Wear a blood pressure monitor for 24 consecutive hours on the day after the home sleep test At the end of the study, participants will be asked to mail back the home sleep test and blood pressure monitors. Prepaid package materials will be provided.