EW.com has the inside scoop on what’s up with Katherine Heigl’s character, Izzie, on Grey’s Anatomy. While rumors of a brain tumor were rampant for awhile, but said to be untrue, inside sources say it is a brain disorder – similar to an aneurysm – that’s causing Izzie’s issues.

While Grey’s Anatomy’s Shonda Rhimes is keeping the specifics under wraps, the problem is similar to an aneurysm… “and every time it flares up, she sees Denny. And sometimes when it really flares up, she shags him,” according to EW.com’s Michael Ausiello.

Will this juicy storyline be Katherine Heigl’s ticket to an Emmy Award win?