Health experts say one way to honor veterans is to provide emotional support and ask how they are doing.

A national study shows that although more than three million veterans face mental health struggles, only half receive the help and care they need.

"I think that our veterans haven been, just as say athletes, have been taught to compartmentalize their feeling and to tuck things away rather than open up. That's the way they've been able to survive on the battlefield. That's the way they've been able to get through different situations. And giving them permission to speak about it is, I think, critical," says Noelle Nevins, a therapist at Family Centers.

Along with checking in on veterans, people are encouraged to invite them to social activities, exercise with them or do a hobby together.

"All of these things increase their sense of connection and has also been shown to elevate positive mood and psychological well-being," says Cragi Bryan, a clinical psychologist at the Wexner Medical Center.

Bryan says warning signs include veterans having severe behavior changes, sleep disruption and saying concerning statements such as, "I can't take this anymore."

"It's really important to be very direct and say, 'You know, I noticed that you seem down. You seem to self-isolate. You're not really yourself anymore, and I'm concerned, and I love you and I'm here and nothing you say is going to change that'," says Nevins.