Nearly two years ago, Thompson found himself having problems with back pain, which he later found out was caused by a non-functioning kidney.
"It wasn't the kind of back pain where you could take a couple of tablets and it would go away, it was the kind of pain that you couldn't do anything," he explained.
"It was a bit surprising at the time because I was a young person who plays sport, you don't really think about health an awful lot."
He added: "It was a no brainer to get the operation to remove the kidney, it wasn't functioning at all, it wasn't doing anything at all except for giving me pain.
"I got that removed a year and a half ago now, and I haven't had back pain since."
You just have to go out and live life to the full. It's certainly made me appreciate that more.
Thompson explained that having one working kidney shouldn't hinder his career as an athlete, but he is more conscious of looking after himself.
"It's something you can't think about too much day-to-day, or you won't go out and enjoy life," he said.
Shortly after having his kidney removed the footballer signed up to be an organ donor to help others who were less fortunate than him and can't lead a normal life because they need an organ transplant.
"I myself am on the donor list and it's something that I was only really aware of after my operation and seeing people when I go to the renal unit, at the Royal on dialysis who are waiting for a new kidney that would completely transform their life," he continued.
"People aren't really aware that there's not enough organs for people to have a transplant.
"It's not a case of when you need a transplant you get one, you wait on waiting list for years and years, unfortunately many people don't make it to the operation.
"But once they recover from the operation, it gives them a completely different life, they can enjoy life, enjoy their family, which is the most important thing."