The 'Lipstick' pair are currently preparing for their semi-final performance on Thursday in order to secure a slot in Saturday's final in Düsseldorf, Germany.
However, the Jedward twin has now been told by doctors that he needs to rest his voice if he wants to recover in time.
"He lost his voice because they've done so many press interviews," a source told The Mirror.
"He's been told to rest his voice as much as possible but with them, that's easier said than done."
Jedward, who are representing Ireland in the competition, have insisted that they do not see the UK's entry, Blue, as a threat.
> Jedward: 'We will lift Eurovision to a new level'
Watch the video for Jedward's 'Lipstick' below: