RETIRED Brisbane defender Jack Frost has detailed the lows he experienced in his battles with concussion, when his personality changed, and he felt like his head was going to “blow off” his shoulders.

Last week, the 26-year-old called time on his career after suffering 14 concussions in six seasons at the Lions and Collingwood.

It was a brutal reality for the backman that he had to stop playing despite being contracted for 2019.

On Monday he told Melbourne radio station SEN what he went through.

“This stuff’s going to happen, and it is something that you know about when you sign up for it. I suppose you never wish for this to happen,” Frost said.

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“Probably the worst of it was last year, where I couldn’t come into the club for maybe six months because I was waking up feeling like I was in a washing machine.

“Any time I did exercise and my heart rate went up felt like my head was going to blow off my shoulders.

“My personality changed a great deal. My partner Kaz, just ask her how much of a pain I was to deal with.

“I think that’s the hardest bit. A lot of people don’t really understand how bad it actually got. In a way it’s relieving, but it’s frustrating that it has to come to this.”

For a long time, the 56-gamer recovered well from the head knocks, but there came a point when that stopped.

“Some people they have symptoms for a week and then they’re fine. For most of mine, it was like that,” Frost said.

“There was just a turning point there where it took a lot longer for me to recover and I started thinking it was pretty dangerous.

“There’s not a huge amount of knowledge around the subject either. It is scary, and you just never know what’s going to happen.”

Having done some work as a mechanic on his off days over the past three years, Frost sees a career path there.

He is also considering staying in football in a player-welfare role.