About 7.7 million people in the United States ages 18 and older have post-traumatic stress disorder (PTSD), a type of anxiety disorder, according to the National Institute of Mental Health (NIMH). When someone has PTSD, she relives a significant trauma. MedlinePlus, a service of the U.S. National Library of Medicine and the National Institutes of Health, explains that PTSD can start immediately after the trauma, or symptoms can start six months or more afterward.
Different types of trauma can lead to the onset of PTSD. The MayoClinic.com points out that the common types of trauma vary by gender. For example, women can develop PTSD after childhood physical abuse, sexual molestation or rape. A physical attack or a threat made with a weapon can also trigger the anxiety disorder. In men, childhood neglect, rape, physical abuse or combat exposure can lead to PTSD. Other types of trauma can also contribute to the onset of the disorder.
PTSD symptoms fall into three groups: avoidance, re-experiencing and arousal. When a PTSD patient is in avoidance, she can feel emotionally numb, detached or have a sense that she does not have a future. She may stay away from reminders of the trauma, which can include people, objects and places. A PTSD patient can re-experience the trauma through flashbacks and intrusive memories. She may have dreams often about the event. MedlinePlus notes that a PTSD patient can have physical reactions to situations when re-experiencing the trauma. During arousal, the patient may have sleeping and concentrating problems. Hypervigilance may occur, in which she is on guard and more watchful. A PTSD patient can have an exaggerated response when startled. For example, the patient may be more jumpy when she hears a loud noise. The patient may also become irritable.