SFC Patterson checks his men at OP Restrepo in Afghanistan in the documentary film "Korengal," by director Sebastian Junger.

The Korengal Valley in Afghanistan wasn’t an easy a place to stay healthy.

From May 2007 to June 2008, the men of 2nd Platoon, Battle Company of the 173rd Army Airborne Brigade held the remote Outpost Restrepo, named after PFC Juan Restrepo, the platoon medic who had been killed in action.

And if you weren’t there — well, you just don’t know what it was like.

“Growing up, I always had that imagination of what war would be like,” said Nicholas Chisenhall, who was deployed to the outpost for five of those months. “You get there, and it’s completely different.”

Living with the platoon were two journalists — Sebastian Junger and Tim Hetherington, who recorded the soldiers’ patrols, firefights, exhilaration and sadness.

In 2010, Junger and Hetherington released "Restrepo," an Oscar-nominated film that chronicled the soldiers’ lives under fire in the area considered to be among the most dangerous in Afghanistan.

Now, Junger has released "Korengal," which examines the men and their responses to warfare. The movie will screen Friday through Sunday at the Gateway Film Center.

“'Restrepo' was for the nation to get it — that we’re at war and this is what war looks like,” Junger said. “'Korengal' is more of an exploration of the effects of combat on young men. Some of the effects are very good; others are traumatic. I feel like we do need to understand that better, and the soldiers need to understand that better to come home successfully.”

Using footage shot during the filming of "Restrepo," the men are depicted in action and interviewed in camp and after returning to their base in Italy.

The soldiers discuss the adrenaline rush of a firefight, the thrill of cheating death, the meaning of bravery to them and the intense brotherhood of the military.

Some soldiers are haunted by the experience. One still instinctively searches for cover — wherever he may be — in case shooting starts.

Another wonders whether God still loves him.

“That comment — ‘You just did what you had to do’ — just drives me insane,” Sgt. Brendan O’Byrne said in the movie. “Because, is that what God’s going to say: ‘You did what you had to do?’ Pat you on the shoulder and say, ‘Welcome to heaven?’ I don’t think so.”

Others miss the experience.

“You make a conscious decision to say, ‘I’m willing to die for this guy,’” Spc. Sterling Jones said in the film. “And that’s a hell of a statement for a guy that you’ve known for two years.

“I love my wife; I love spending time with her. I like to see my mom. But if I could get on a bird and go back — yeah, I would.”

A native of the Boston area who now lives in New York, Junger is a veteran war reporter, having covered battles in Africa and Afghanistan.

“It’s history-making in its most dramatic form, and the consequences are enormous for people — and humanity, really,” said Junger, 52.

“A lot of the wars that I covered are ongoing tragedies, and the world needs to make a responsible decision on how to deal with them, and the world can’t if there’s no media coverage.

“It feels like there’s a real moral duty to cover this. It’s also very intoxicating work.”

Junger and Hetherington — who was killed covering fighting in Libya in 2011 — visited Outpost Restrepo 10 times, doing everything the soldiers did except pulling guard duty and firing weapons.

And they gained the soldiers’ trust.

“Gradually, over the course of the year,” Junger said, “that trust just kept increasing.”

Chisenhall, a 24-year-old from Cincinnati who left the Army in 2011, is seen only in the background in Korengal. But when people ask him what his deployment to Afghanistan was like, he tells them to watch the movies.

“For anybody to really see what it is like over there, for any questions they may have ... that’s as close as it gets. Even with that, if you really haven’t been there, you’re still far from really experiencing it. ... Watching the film, I felt like I could almost touch it.”