This is the latest in a string of health scares for the former leader, who was jailed for massacres committed while he was in power in the 1990s.
Fujimori collapsed in prison in Lima on Tuesday and was rushed to a clinic. Doctors said his life was in peril.
He is now being stabilized with medication, and will later be weaned off that medication to see how he does, his doctor Alejandro Aguinaga told the TV station N.
Fujimori is serving a 25-year sentence for human rights abuses and corruption.
He was convicted in 2007 for his role in killings by a death squad targeting supposed guerrillas.
He has since been in and out of hospital with heart, back and stomach trouble and growths on his tongue, which has been operated on several times for cancer.
Fujimori was president from 1990 to 2000.
Last year his daughter Keiko Fujimori narrowly lost a presidential election to Pedro Pablo Kuczynski.
Keiko Fujimori's populist Popular Force party nevertheless controls the single-chamber legislature.
Kuczynski has suggested he might consider a pardon for Fujimori, but denied any backroom deal with Popular Force.
Eyewitness? Submit your stories now via social or:
Email: news@pulselive.co.ke
