The 90-year-old former president was taken to the Houston Methodist Hospital in an ambulance after he experienced a shortness of breath on Tuesday evening, said the report.
He will be held in the hospital for observation.
George H.W. Bush, the son of a senator, was born in Massachusetts. He served one presidential term, from 1989-1993, before being beaten in polls by Bill Clinton in 1992. Eight years later, his eldest son George W. Bush took over as US president.
Another son of George Bush senior, Jeb Bush, is contesting in 2016 White House race .
In 2013, he grabbed headlines after he shaved his head to show support for the 2-year-old son of a security agent who was losing his hair as a side-effect of treatment for the cancer.
George and Barbara Bush had lost their second child, 4-year-old Robin Bush, to leukemia almost 60 years ago.