**Background:** Over 3 million U.S. veterans have served since 2001 (OEF/OIF/OND), and prior research suggests they have poorer physical health than nonveterans, including musculoskeletal disorders, respiratory problems, obesity, and cardiovascular risk factors. However, few large-scale epidemiological studies have systematically compared post-9/11 veterans to demographically matched nonveterans, and no published analyses have tested statistical interactions between veteran status, sex, and physical health. This study aimed to examine the association between veteran status and 24 physical health conditions, evaluate differences by sex, and classify conditions within Healthy People 2020 targeted topic areas.
**Methods:** The 2018 Comparative Health Assessment Interview Research Study (CHAI) was a cross-sectional, nationwide survey of post-9/11 veterans and nonveterans. The veteran sampling frame (n=67,500) was derived from the VA's 2015 USVETS database, with stratified random sampling and oversampling of women. A comparison sample of nonveterans (n=16,843) was drawn from the GfK KnowledgePanel®. The veteran response rate was 39.5% (n=15,170 eligible, returned surveys); after exclusions, 15,160 veterans were analyzed. For nonveterans, the completion rate was 56.5% for active panelists (n=4,458) and 8.4% for inactive panelists (n=752), yielding 4,533 nonveterans after exclusions. Data were self-reported via a web-based mobile application or computer-assisted telephone interview. Physical health outcomes were assessed using a modified National Health Interview Survey question asking whether a doctor had ever told respondents they had each condition. Obesity was derived from BMI (≥30 kg/m²). Twenty-four conditions were classified into 11 health topic areas, 10 based on Healthy People 2020. Statistical analyses used weighted data with Rao-Scott chi-square tests, bivariable and multivariable logistic regression, and relative risk calculations. Adjusted odds ratios controlled for sex, age, race/ethnicity, education, marital status, and Census region. Interactions of veteran status by sex were tested for each outcome.
**Key Results:** Most respondents were aged 25–44 years, male (82.7%), White non-Hispanic (66.4%), and married. Veterans had significantly higher prevalence than nonveterans for 16 of 24 conditions. The largest prevalence differences were for back/neck pain (49.3% vs. 22.8%, p<0.001), fractures/bone-joint injuries (47.6% vs. 29.2%, p<0.001), obesity (39.9% vs. 36.6%, p=0.002), hypertension (27.8% vs. 22.5%), high cholesterol (26.9% vs. 21.3%), arthritis (26.2% vs. 10.9%), sleep apnea (20.8% vs. 9.7%), and migraine (19.1% vs. 10.3%) (all p<0.001 except obesity p=0.002). Diabetes was significantly lower in veterans (4.8% vs. 7.2%, p<0.001; RR=0.67, 95% CI:0.58–0.78). After adjustment, the strongest associations with veteran status were for traumatic brain injury (AOR=5.57, 95% CI:3.82–8.14), hearing loss (AOR=4.62, 95% CI:3.50–6.09), chronic fatigue syndrome (AOR=3.80, 95% CI:2.52–5.73), arthritis (AOR=3.40, 95% CI:2.92–3.97), back/neck pain (AOR=3.36, 95% CI:2.98–3.79), and spinal cord injury (AOR=3.31, 95% CI:2.32–4.73) (all p<0.001). By sex, women had dramatically higher odds of bladder infections (males:females AOR=0.08, 95% CI:0.04–0.18), multiple sclerosis (AOR=0.36), chronic fatigue syndrome (AOR=0.42), cancer (AOR=0.47), and irritable bowel syndrome/colitis (AOR=0.50). Men had higher odds of sleep apnea (AOR=2.02), hypertension (AOR=1.70), and high cholesterol (AOR=1.50). Significant interactions of veteran status by sex were found for obesity (p=0.028) and migraine (p=0.011). Among veterans, obesity was greater for males than females (AOR=1.30, 95% CI:1.14–1.47), while no sex difference was found among nonveterans. For migraine, the female predominance was stronger among nonveterans (males:females AOR=0.28) than veterans (AOR=0.38).
**Clinical Implications:** Post-9/11 veterans carry a substantially higher burden of physical health conditions compared to demographically similar nonveterans, particularly traumatic brain injury, hearing loss, chronic fatigue syndrome, and musculoskeletal disorders. The elevated odds of obesity, hypertension, high cholesterol, and sleep apnea in veterans underscore the need for targeted cardiovascular and metabolic risk reduction. The strong sex-specific patterns—with women at higher risk for bladder infections, migraine, and autoimmune-type conditions, and men for hypertension and sleep apnea—highlight the importance of sex-stratified clinical screening and intervention. Notably, many prevalent veteran conditions (e.g., TBI, migraine, irritable bowel syndrome) fall outside Healthy People 2020 topic areas, and no veteran-specific topic area exists, suggesting that national health guidelines may inadequately address veteran health needs. Integrated physical-mental health approaches remain critical given the known associations between PTSD and physical morbidity in this population.