Former US President George HW Bush, 93, has been taken to a hospital in Maine after experiencing low blood pressure and fatigue, a family spokesman said on Twitter.
Bush, the oldest living former US president, will likely remain at Southern Maine Health Care for a few days for observation, said the spokesman, Jim McGrath.
“The former president is awake and alert, and not in any discomfort,” McGrath wrote on Twitter on Sunday.
Mr Bush, who has been confined to a wheelchair since developing Parkinson’s disease, has required hospital treatment several times in recent years.
Mr Bush was hospitalised in Texas last month for treatment of an infection that spread to his blood, and stayed there for nearly two weeks.
He was admitted to the hospital a day after he attended the funeral of his wife, Barbara, the former first lady who died on April 17. The couple had been married for 73 years.
Last April he spent two weeks in the hospital for treatment of pneumonia and chronic bronchitis, and was hospitalised for 16 days in January 2017 for pneumonia.
Mr Bush was also hospitalised in 2015 after falling at home in Maine and breaking a bone in his neck, and spent a week in hospital in in December 2014 with shortness of breath.
He spent Christmas 2012 in intensive care for a bronchitis-related cough and other issues.
On Saturday, Mr Bush attended an American Legion event in Kennebunkport, Maine to mark the upcoming Memorial Day with military veterans and his former national security adviser Brent Scowcroft, according to a post on Mr Bush’s official Twitter feed.
Mr Bush is the father of former Republican president George W Bush, who served two terms from 2001 to 2009, and former Florida Governor Jeb Bush, who unsuccessfully sought the 2016 Republican presidential nomination.
Mr Bush, the country’s oldest living ex-president, served a single term in the Oval Office from 1989 through 1993.