Former soldier Mark Compain joined the Defence Force as a 16 year old and served for 21 years in various conflict zones including East Timor, Bosnia and Afghanistan.
It was on his second tour of Afghanistan that he realised he wasn’t coping.
"I walked into the medical centre, burst into tears and said 'I can’t do this anymore,'" he told 1 NEWS.
He was then medically evacuated out of the conflict zone, diagnosed with Post Traumatic Stress Injury (PTSI).
"It was devastating because you knew people were gunna be judging you, and you were judging yourself.
"I didn’t think I was injured, I wondered what was wrong with me. I was like 'toughen up', ya know? Because I’ve got a job to do and people are relying on me. And I didn't go to Gallipoli, what am I moaning about?" he said.
It's stories like this that prompted the theme for this year's Poppy Day appeal.
The theme for this year's appeal, 'not all wounds bleed', highlights the fact that mental health injuries are the most common, but least understood, of all wounds suffered by New Zealand servicemen and women.
RSA National President BJ Clark said the RSA is committed to providing help to former members of the military who have served in deployments.
"There's a growing demand for our support services, including an increasing number with service-induced mental health injuries."
"These injuries may occur because of exposure to trauma or stress arising from combat, operational duties in a conflict zone, or other traumatic or serious events such as civil defence emergency or disaster relief," Mr Clark said.
The New Zealand Defence Force said it's put a focus on mental health in recent years, but wants to learn how to do more. It said it's looking to other defence forces overseas to learn from them about how better to support staff.
"Symptoms of PTSI include reliving the event, including nightmares, flashbacks, or intrusive thoughts. In addition, sufferers can experience avoiding thoughts, feelings, or situations that serve as reminders of the event, feeling numb or cut off from others, being easily startled and being vigilant for signs of danger," NZ Defence Force Medical Director Dr Paul Nealis said.
The NZDF estimates around 100 soldiers are dealing with PTSD, but not necessarily from being in conflict.
"We do monitor people prior to any deployments that they would be placed on, and also on return, and we follow that up on a regular basis," Brigadier Andrew Gray said.
"We are looking at trying to, as an organisation, understand what mental health challenges there are as a result of deployment, or any other thing."
Mr Compain said the most important thing is that people treat mental health issues as a war wound.
"This is a legitimate injury. And you are not weak… this is a legitimate wound."
It's hoped raised awareness and better understanding will help this wound heal.