Former President George H.W. Bush will spend a fourth night in a Texas hospital, his office announced Friday.
Bush, 90, was taken to Houston Methodist Hospital by ambulance as a precaution Tuesday after experiencing a shortness of breath.
He has remained at the hospital for observation since then, though his office said in a statement that the 41st president remains in "high spirits and continues to make progress."
Bush -- the father of former President George W. Bush and former Florida Gov. Jeb Bush -- spent Christmas at the hospital and received visits from his wife, former First Lady Barbara Bush, and from his son and daughter-in-law Neil and Maria Bush.
Bush was previously hospitalized in November 2012 with a persistent cough and stayed for nearly two months when he developed a fever.
In June, he made headlines when he celebrated his 90th birthday by skydiving.