Lamar Odom's Kidneys Failing ... Transplant in Play

Lamar Odom's kidneys are failing and he may need a transplant ... TMZ has learned.

Sources familiar with Lamar's medical condition tell TMZ, the organs that have failed have all bounced back in significant degree, except the kidneys. As one source put it, "His kidneys are shot."

Lamar is at Cedars-Sinai Medical Center in L.A., and we're told he will undergo 6 hours of dialysis a day, but the end game may well be a transplant.

As for his move from Vegas to L.A., our sources say the main reason for the change is so Lamar can get better specialized care. His condition has improved, but the move is not a signal he's out of the woods.

We're told doctors at Cedars will be performing brain tests, which will help determine the extent of damage the strokes had on Lamar.