Former US President George Bush Senior has been taken to hospital after suffering from a shortness of breath, his spokesman says, SIA reports quoting the BBC.
Mr Bush, 90, was taken to the Houston Methodist Hospital as a precaution, and "will be held for observation, again as a precaution", said Jim McGrath.
Two years ago, Mr Bush was treated in the same hospital for more than two months for a bronchitis-related cough and other issues.
He was president from 1989 to 1993.
He is the oldest living former US president and a World War II veteran. He can no longer use his legs, but in June celebrated his 90th birthday by making a tandem parachute jump.
His son George W Bush served as president from 2001 to 2009.