"I never thought I had PTSD," said Miller, a door gunner on a Huey helicopter in the Vietnam War.
Recently diagnosed with PTSD, Miller, 68, of Palm Bay, said he saw a lot of combat but always thought that others had seen more than he did, so he could not complain about anything.
"I realize now that I pretty much been lying to myself for 47 years," he said.
Psychologist Fairchild said many people use work or other things to try to suppress the condition.
As an Army veteran, he served 21 years, half of his career in combat health care and retired as a lieutenant colonel. He operates Baytree Behavioral Health in Melbourne.
He said troops having difficulties have at times been told to "suck it up," and move on. That puts off treatment and prolongs the suffering. "If we stuff it in the closet, it builds up and pushes on the door," he said. "We carry more baggage if we don't deal with it. The emotional bucket starts to overflow."
Suppressing such emotions for a long time can lead to them being released in a big wave, Fairchild said.
"PTSD is like being hit by shrapnel," he said. "It goes in and it stays there. When it comes out, it hurts."
Neil Johnson of Titusville was seriously wounded in Vietnam. His wounds didn't kill him, but surviving them has meant a long battle with PTSD.
"My biggest problem that I'm going through right now is guilt," said Johnson, 66, as tears welled in his eyes. "When I was medevac'd out, there were eight dead. I get to breathe and they are dead. The guilt is my biggest problem. It just eats at me."
Such feelings are common among combat survivors.
Bill Vagianos' best friend was killed in Vietnam. Vagianos said he returned from the war suffering from "survivor guilt."
After the war, he went to college, eventually earning a doctorate in psychology.
Today, the Merritt Island psychologist still copes with his own PTSD, even as he helps other vets deal with theirs.
"Over the years I have been able to help veterans who were in despair and homelessness," he said.
Some PTSD sufferers say they have veteran friends who don't realize that they have a problem and probably should be checked for the disorder.
Carlos Gonzalez Alayon, 67, of Merritt Island is a veteran of the Vietnam War who said he had long suffered from PTSD but did not know what his troubles were about.
It wasn't until another veteran, who had observed his actions, told him he should be checked that he sought help.
"I didn't know what PTSD was," he said. "I said, 'Talk to me in English.'"
People need to understand PTSD's effects on a person suffering from it, and how it affects the rest of society, Fairchild said. People need to know if they or a member of their family is suffering from PTSD to get support.