The 83-year-old has been receiving treatment for prostate cancer for some time but has now taken a 'reaction to a new treatment for [his] prostate and strengthening [his] bones'.
In a statement Archbishop Tutu said "It is benign and these issues are par for the course."
He was due to travel to Rome for the World Summit of Nobel Peace Laureates but has cancelled the trip.
Media reports suggest his daughter, Mpho Tutu, said there was no crisis and her father was staying at home as he adjusted to new medication.
Archbishop Tutu has been battling prostate cancer for the past 15 years and has undergone successful treatment in the past.