Inclusion Criteria (for observation and hydrocortisone treatment groups):  Screening positive for PTSD Diagnostic and Statistical Manual of Mental Disorders-5 Criteria A (felt a threat to life or injury to self or neonate) Postpartum hemorrhage or emergency cesarean delivery Owner of a smart phone or email account  Exclusion Criteria (for observation and hydrocortisone treatment groups):  Active uncontrolled psychological disturbances identified by current psychiatric admission Psychiatric consult during admission, or need for hospital appointed sitter during admission Non-English speakers requiring a translator Current corticosteroid use or corticosteroid use during the study period (including betamethasone for promoting fetal lung maturity) Cognitive impairment identified by medical chart review or patients requiring a legal guardian for medical decision making  Exclusion Criteria: (additional criteria for participants that will receive hydrocortisone)  Self-reported hypersensitivity to hydrocortisone Inability to consent patient and administer study drug within 12 hours of a traumatic event Weight < 45 kilograms (kg) or >120kg Subjects with systemic active infections (e.g. viral, bacterial, fungal, protozoan, or helminthic) Subjects with uncontrolled hypertension, renal insufficiency, or decompensated congestive heart failure Subjects with inflammatory bowel disease Subjects with active or latent peptic ulcers