Former US president George HW Bush was taken to a Houston hospital on Tuesday night after experiencing shortness of breath, a family spokesman said.
Bush, 90, would be held at least overnight at Houston Methodist Hospital as a precaution, said the spokesman, Jim McGrath. He is expected to be fine.
The former president spent nearly two months at Houston Methodist - including a week in intensive care - in late 2012 and early 2013 while suffering from a bronchitis-related cough and fever.
Bush, the oldest living former president (he is about four months older than Jimmy Carter), has a form of Parkinson's disease and often uses a wheelchair or scooter. He and his wife, Barbara, frequently make appearances in Houston, and he went sky diving on his 90th birthday in June.
Last month, he traveled to his presidential library at Texas A&M University, where his oldest son, former president George W Bush, unveiled his book, "41: A Portrait of My Father."