Lauda's doctors now worried about kidneys

After a string of positive messages regarding Niki Lauda's revalidation progress in the past weeks, reports have now come out that the Austrian's health has worsened again as he has kidney problems.

Lauda was recently operated on in order to save his life after he collapsed during his holiday on Ibiza. A host of complications forced the medical team to transplant one of his lungs.

The enormous amount of pills that the three-time F1 champion has to take daily to make sure his body doesn't reject the new lung has put too much pressure on his kidneys. It's clear that the situation has grown more complicated because the kidney that's causing trouble was once transplanted as well.

It could take up to a year for Lauda's body to fully accept his new lung, OE24 reports. The doctors are afraid the intense use of medicine could severely damage his kidney. However, the revalidation process will now take longer than initially thought.

The first prediction was that Lauda could resume his work for Mercedes relatively quickly. A radical change of lifestyle is necessary for the next six months, afterwards the Austrian can live his life in a normal way again. The doctor has advised Lauda not to fly for these six months though, which could prove to be a major complication.