At 26 years of age, the day she arrived in Vietnam in 1967, Sarah Blum was one of the older nurses tending the wounded at the 12th Evac hospital in the infamous Iron Triangle.

All operations were there, Blum said, and the battlefield, known for the ferocity of the fighting that went on there, was all around.

On any given day, the North Vietnamese hit units like the Wolfhounds, the Manchu and the Bobcats, and the 12th would receive and treat the mass casualties.

Blum saw the worst.

In her new book “Warrior Nurse: PTSD and Healing,” Blum lays out the experience before her readers.

”Everything was strange and different,” Blum said. “I had no way to relate to so many things. Like just going to the 90th Replacement Battalion. We had this little building that we stayed in with bunk beds. Rats running around. I wasn’t used to that.”

The book follows Blum back to the United States in 1968, to a country tearing itself apart — young people burning their draft cards, marching in the streets, torching American flags.

“It was difficult and painful,” Blum said. “I didn’t know where I fit in. I wasn’t a civilian, I wasn’t one of them, and they were angry at those of us who’d been to Vietnam. So I didn’t want to tell anyone who I was. Here I’d been to war. I knew what that was, but this was different. One time, a protester attacked me with eggs and spat at me. I didn’t feel safe at home.”

As the narrative continue, Blum guides her reader through the process of dealing with PTSD, which manifested stateside while she was driving to work one morning during rush-hour traffic, and how she learned about PTSD as a professional psychotherapist.

She describes PTSD, what it is, how it affects people, how it manifests differently in different people, how it affects the brain and body, and then identifies resources that could help the sufferer heal without having to attend therapy or a group.

Later, she relates her experiences in Washington, D.C., where she went for the Salute to Vietnam Veterans. There she testified at the first PTSD hearings ever, at the first hearing on Agent Orange, and the “tremendous emotion” that poured out of her fellow veterans. She also took time to visit the Vietnam War Memorial.

“When we tell our stories is when it all comes alive again. But I never know from one moment to the next what’s going to come up. Only when the emotions come up now, I let ‘em. I don’t want to ever close them again,” Blum said.

Here are the salient details of the launch of “Warrior Nurse: PTSD and Healing:”

When: 3 p.m., Friday, March 14.

Where: Seattle Opera House, Tagney Jones Hall, 363 Mercer St. and 4th Avenue

What: To celebrate Blum’s latest book, Seattle Opera Veterans Choir will give a special performance in addition to inspirational speakers, a live reading by Blum, and then book signings.

It is Blum’s second book. Her first, published in 2013, was “Women Under Fire: Abuse in the Military,” a searing examination of sexual abuse in the armed forces.