SAINT LOUIS PARK, Minn. - Daniel Hess, a licensed psychologist at HealthPartners, devotes a lot of his work to help people struggling with PTSD.

“All mammals, including humans, react to the perceived threat in biologically similar ways,” Hess says. “We are hardwired to do so.”

Hess says, for some people, that threat response, often referred to as fight or flight, doesn't shut off and becomes what we call post-traumatic stress disorder.

Signs that someone may be struggling with it?

“Intrusive re-experiencing of the traumatic event by memory, thought and dreams,” says Hess. “Actions of avoidance - trying not to think about things that have happened,” he adds. “Persistent sense of being in a state of threat that doesn't shut off.”

Hess says he refers to PTSD, not as an illness, but rather an injury to the brain.

According to him, it's usually caused by an incident, or a limited number of incidents, over a certain period of time.

“That can include things like combat, rape, assault, medical procedure, natural disaster,” says Hess. “It has a clear beginning and end.”

So what does treatment look like?

Hess says talk therapy is an important part, but that there generally needs to be more than that.

“A treatment that incorporates what's happening in the body and the lower areas of the brain, the limbic system and the brain stem, which is where the neurological threat response system is managed,” says Hess.

Hess says what's known as EMDR therapy is very common to help treat PTSD. He also adds that practices like yoga are helpful.