The DJ was set to perform at the Future Music Festivals in Brisbane and Perth this past weekend but was forced to pull out of both performances due to his illness.
His camp released a statement on Saturday that said " Over the past couple of days we have been monitoring his condition and we have all been optimistic about him being healthy enough to perform.
"Unfortunately the doctors are not willing to discharge him at this time so he will be unable to appear at tonight and tomorrow's performances.
"Avicii will continue to rest throughout this week and looks forward to playing the remaining shows on this tour."
Those remaining dates for the festival are taking place next weekend, however his website does not list them as of Monday morning. His next scheduled date according to the site is in Mexico on March 15th.
His Facebook page only lists past events from 2012.