Doctors at the Fundacion Favaloro hospital issued a statement saying she should be in "strict repose" and should avoid air travel for 30 days. Still, her spokesman Alfredo Scoccimarro said she was recovering well and is "in excellent spirits."
That period of rest would keep her out of the campaign for legislative elections on Oct. 27. Polls indicate that her party could suffer losses.
Supporters cheered and chanted slogans as her official car drove out of the hospital under heavy guard.
Fernandez, 60, underwent surgery on Tuesday to drain a blood clot that was pressing on her brain and causing pain. Officials said it was caused by a previously unreported blow to the head that she suffered on Aug. 12.