The 36-year-old is currently in the renal unit of Auckland City Hospital, where no word has been given about his condition since he was admitted.
But Lomu, who is credited as rugby union's first global superstar, spoke about his condition in the New Zealand Woman's Weekly magazine today after he signed an exclusive contract with them.
Lomu, who scored 37 tries during a memorable 64-cap Test career with the All Blacks, made his last public appearance at the World Cup opening ceremony in Auckland just over three weeks ago.
He had a kidney transplant in 2004, the organ being donated by New Zealand radio personality Grant Kereama, but that now appears to be failing him.
"It just went pear-shaped one afternoon," Lomu told the magazine.
"I thought it was just a cold or food poisoning. I couldn't put my finger on it.
"All I knew was that I didn't feel well and I couldn't hold any food down for about 10 days. I was basically starving.
"Last Friday, I was just about to leave for a function and I crashed. My kidney was failing and my body had become so toxic it started to shut down."
Lomu has undergone numerous tests, with the results set to dictate whether or not he requires another transplant.
Lomu's wide Nadene said: "They've said there's a very slim chance this kidney may survive. So for now Jonah's having dialysis every day and a load of other treatments to see if it can be revived."
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Gilbert Blitz 8S rugby cleat is a great cleat at a great price of $69.99. Get a new pair of cleats today.
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
The All Blacks Performance t-shirt is black with hints of blue from the training jersey. Very Cool.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.