"President Bush had a good day and his prognosis remains positive," spokesman Jim McGrath said in a brief statement issued Wednesday evening, a day after Bush was admitted to Houston Methodist Hospital.
McGrath added that Bush would remain at the hospital for another night "as a precaution."
Bush was admitted to the same hospital in November 2012 for treatment of bronchitis and related ailments before his discharge seven weeks later in mid-January of 2013.
His latest health scare unfolded on Tuesday evening, when the former president suffered shortness of breath and was taken by ambulance to Houston Methodist to be held for observation, McGrath said.
Bush, a Republican, grew so ill during his previous hospitalization that he was believed at one point to be near death, and members of his family gathered around him.
He marked his 90th birthday this year by taking a tandem parachute jump near Kennebunkport, Maine. His eldest son, former President George W. Bush, this year published a best-selling book about his father, titled "41 - A Portrait of My Father."