A statement on the X Factor winner's Facebook page said he'd been instructed to cancel all upcoming performances and appearances in order to focus on his health.
The post read: "Unfortunately James Arthur has been diagnosed with acute exhaustion and instructed to rest for several days by his doctor. Regretfully, he has been forced to cancel all engagements during this period.
"James would like to apologise to his fans for any disappointment caused to them by these cancellations and he hopes to get back to full health as soon as possible."
James has been in the headlines this week after vowing to quit Twitter and then becoming embroiled in a row with fellow X Factor contestant Lucy Spraggan.
Lucy had criticised James' use of the word 'queer' in a rap that surfaced online. He apologised for the slur but Lucy later posted images on Twitter showing screenshots of texts allegedly sent to her by James, who was unhappy Lucy had spoken out against his use of the word.
James, who helped switch on the Oxford Street, London Christmas lights earlier this month, has been promoting his debut album James lately, which features the single 'You're Nobody 'Til Somebody Loves You'.