The businessman, played by Jordan Smith, begins to suspect something is wrong when he blacks out at home by himself.
He sets up a camera to see what happens when it occurs again, but when nothing shows up he goes to the doctor, who identifies his symptoms as epilepsy.
A Neighbours insider told the Daily Star: "Andrew is devastated when he discovers he's got epilepsy.
"He's in the prime of his life and is shocked by the news as the attacks can happen at any time.
"Andrew is going to struggle with living with epilepsy. It will have a huge impact on his life."
Smith recently spoke to Digital Spy about life on Neighbours under its new showrunners Richard Jasek and Alan Hardy, claiming: "[There's been] a definite, massive change.
"They look out for you - even though they're running an entire show of 500 people, they've got all the time in the world to talk to you. They've brought a new life into it, I guess… It's a really good change that's going on at the moment."
Watch Jordan Smith's interview with Digital Spy below: