"That's why we've got two of them, if one gives in we've got a spare, that's how important they are," the Mount Warrigal man said.

Like many people, he didn't realise the significance of the two organs, the size of a fist, "working quietly in the background" until his "packed it in".

"One particular day I just felt ill - that's what happens. By the time I discovered I had kidney disease I'd lost about 80 per cent of kidney function," he said.

"You don't even know they're not working until there's a big problem. You can lose up to 90 per cent of function without even knowing."

Wollongong Hospital Renal Service kidney specialist Jim Greenstein said kidney disease was on the increase and killed more Australians each year than breast cancer, prostate cancer and road deaths.

"There is no cure but early detection can increase the life of your kidneys and keep you feeling your best as long as possible," Dr Greenstein said.

"One in three Australians are at risk of renal disease and diabetes is well and truly the biggest single cause of renal failure. Almost 40 per cent of all patients who present with renal failure are diabetic."

Dr Greenstein said the good news was that many contributing factors could be minimised.

"Controlling blood sugar levels, losing weight, eating properly, exercising, not overdoing the alcohol, these things can all make a huge difference," he said.

"Not smoking is crucial, if you smoke the rest almost becomes irrelevant. Smoking has a terrible outcome in kidney disease."

Mr Barracosa didn't know the warning signs and his diagnosis came "a bit too late". He was told he would have to "go down the dialysis and transplant path".

"But once I found out I had kidney disease I made changes, and I made my kidneys last 11 years," he said.

"They told me five years but I prolonged my health and that was really important to me."

When Mr Barracosa got his new kidney in 2001 it was like winning the lottery.

"I consider these little organs an incredible marvel of biological engineering. They're like the environmental agency of the body that keeps everything in balance," he said.

"Okay they might not be as sexy as the heart, brain or lung, they just sit there in the background doing what they do, but without them, none of the other organs would survive very well."

Mr Barracosa is using Kidney Health Week to "elevate the kidney".

"I just want everyone to make a conscious effort to see their GP and ask to conduct a kidney health check, it's really simple."

Visit kidney.org.au or call 1800 454 363.