Mubarak also suffered from a rapid heart beat, the newspaper Al Masry, Al Youm reported. Proceedings resumed when his condition improved.
Security at the Police Academy in New Cairo was tight.
Mubarak is on trial with former Interior Minister Habib al-Adly and six other former officials on charges that include corruption and killing protesters during the 2011 protests. Hussein Salem, a businessman who is a fugitive, is also charged in the case.
Two top security officials in Mubarak's government -- Hamdy Badeen, who headed the Military Police, and Khaled Tharwat, the National Security Agency chief -- were expected to testify.
Mubarak was convicted of the charges in 2012 and sentenced to life in prison. He won an appeal last year and is being retried.
The 85-year-old, who ruled Egypt from 1981 to 2011, is in poor health.