(NEWS CENTER) -- Over the years we've learned more about the dangers first responders face; higher risks for cancer; heart disease; injuries, but there's an injury that's been going untreated within many of these men and women.

It's something that isn't talked about, at least, not in their careers.

Post Traumatic Stress Disorder.

It affects social interactions, sleep patterns and relationships. For some, it makes an already short career even shorter.

So how do we save those who put their lives at risk for us? It starts with more conversation.

"It turned into two different departments, the department before the Miami fire, and the department after the Miami fire." Chris Matthews will never forget one of the last fires of his career.

In May 2012, the USS Miami was set on fire while docked at the Portsmouth Naval Shipyard. Matthews was one of the firefighters sent into the burning submarine.

"You're going in a hole where smoke and fire and everything is coming out," said Matthews about the night. "When I first went in sailors were absolutely bailing out and they had their breathing apparatus and they were running for their lives, and justifiably so."

Crews fought that blaze for 12 terrifying hours, then went home; but not everyone moved on.

"I was having trouble sleeping, eating, concentrating. I was angry. I basically became a shut in." It wasn't until months later when Matthews was hospitalized for respiratory issues, that someone finally said the words, "Post Traumatic Stress Disorder."

"It didn't happen from a concussion or something falling on your head, but the brain is not functioning correctly," said Mike Crouse, with Professional Fire Fighters of Maine.

For Matthews, after 16 years in the fire service, it was a career-ender. It took nearly four years for his former job to acknowledge PTSD was work-related.

"The things that we see you can't unsee them. The things that you hear, you can't take back," said Biddeford firefighter and EMT, Tim Sevigny. 'Those go somewhere, they go to the back of your mind and they're just there."

Sevigny says that for many, that PTSD comes on more gradually.

"We had a family dog and we had to put her down. When the doctor was giving the dog the medicine, I had this feeling come over me and I started seeing 20 years of dead people, people I had seen over the years just flashing across my face like a screen. I had to get out."

Faces. Scenes. They become haunting.

"You build these walls. You get desensitized to life. What is important to your family is no longer important to you," said Sevigny.

Biddeford Fire and Rescue is one of the first departments in the state to pick up the conversation about PTSD.

"We found behavioral health is not being talked about in school. It's not talked about in officer class."

Firefighters and paramedics are taking classes on behavioral health, training each other on warning signs, and speaking with psychologists; but it's been a slow process.

"We've looked at a lot of programs and we still to this day have not found anything from maintenance for firefighters." Maintenance to keep these men and women healthy physically and mentally, and on the job.

Nearly four years later, Matthews still can't go back to the shipyard. Even sharing his story was difficult, but he hopes it will help spark even more difficult conversations.

"Don't be too proud to talk about it," said Matthews. "Don't think it can't happen to you."

Other major cities in Maine have started focusing on mental health and trying to break through the stigma surrounds it. PFFM is also working to open its own emergency health clinic, hoping to offer another safe space for those suffering silently.