The symptoms of PTSD can be grouped into four main categories:

1. Intrusion: People with PTSD often experience intrusive thoughts, nightmares, or flashbacks related to the traumatic event. These intrusive symptoms can be distressing and uncontrollable, causing the person to relive the trauma as if it were happening again.

2. Avoidance: Individuals with PTSD may actively avoid people, places, or activities that remind them of the trauma. They might also avoid talking about the event or their emotions surrounding it. Avoidance may extend to numbing emotions or feeling detached from loved ones.

3. Negative alterations in mood and cognition: People with PTSD may experience negative thoughts and beliefs about themselves or the world. They might struggle with memory issues, have difficulty concentrating, feel guilty, experience a decreased interest in previously enjoyed activities, or have a persistently negative mood.

4. Arousal and reactivity: This category involves experiencing heightened arousal or sensitivity, leading to irritability, angry outbursts, difficulty sleeping, hypervigilance, and an exaggerated startled response. Individuals with PTSD may also have difficulty concentrating or experience physical symptoms related to anxiety.