The possible truth about the real condition of Dr. Izzie Stevens' character, played by Katherine Heigl, on ABC's "Grey's Anatomy" has been revealed. As multiple reliable sources informed to EW's Michael Ausiello, the reason behind Izzie's hallucination of having interaction with dead people is a matter of health- and brain-related.
EW noted that Izzie's health problem is similar to an aneurysm, a blood-filled dilation which most commonly occurs in arteries at the base of the brain. The good news is that the disease will not be fatal. In the meantime, there is no confirmation from the network about this potential aneurysm disorder.
Previously, there are several speculations circulating around Izzie's condition regarding her recently complex situation with her deceased fiance, Denny Duquette. The number one speculation has stated that Izzie's character may suffer from a brain tumor.