Posttraumatic stress disorder (PTSD) is defined as a psychiatric disorder; however, PTSD co-occurs with multiple somatic manifestations. People living with PTSD commonly manifest dysregulations in the systems that regulate the stress response, including the hypothalamic-pituitary-adrenal (HPA) axis, and development of a pro-inflammatory state. Additionally, somatic autoimmune and inflammatory diseases and disorders have a high rate of co-morbidity with PTSD. Recognition and understanding of the compounding effect that these disease states can have on each other, evidenced from poorer treatment outcomes and accelerated disease progression in patients suffering from co-morbid PTSD and/or other autoimmune and inflammatory diseases, has the potential to lead to additional treatment opportunities.