PTSD (Posttraumatic Stress Disorder) is a mental health problem that can develop after experiencing or witnessing a traumatic or life-threatening event such as combat, sexual assault, or a natural disaster. Symptoms include reliving the traumatic event through flashbacks or nightmares, avoiding situations that trigger memories of the event, negative changes in beliefs and feelings, and feeling tense and hypervigilant. PTSD symptoms can last for months or years and cause great distress if untreated. Seeking treatment, which may involve medication and counseling, can help manage PTSD and related issues like depression or anxiety.