创伤后压力心理障碍症（英文：post-traumatic stress disorder；PTSD），又译创伤后压力症、创伤后压力症候群、创伤后精神紧张性障碍、创伤后压力失调、重大打击后遗症。指人在遭遇或对抗重大压力后，其心理状态产生失调之后遗症。这些经验包括生命遭到威胁、严重物理性伤害、身体或心灵上的胁迫。有时候被称之为创伤后压力反应（post-traumatic stress reaction）以强调这个现象乃经验创伤后所产生之合理结果，而非病患心理状态原本就有问题。

Posttraumatic stress disorder (PTSD) is a mental disorder that can develop after a person is exposed to a traumatic event, such as sexual assault, warfare, traffic collisions, or other threats on a person's life. Symptoms may include disturbing thoughts, feelings, or dreams related to the events, mental or physical distress to trauma-related cues, attempts to avoid trauma-related cues, alterations in how a person thinks and feels, and increased arousal. These symptoms last for more than a month after the event. Young children are less likely to show distress but instead may express their memories through play. Those with PTSD are at a higher risk of suicide.