President George H. W. Bush was admitted to a Houston hospital to be treated for bronchitis.
The 88-year-old former president is undergoing treatment at Methodist Hospital for a "lingering cough," Bush spokesman Jim McGrath told Fox News.
"President Bush has been in and out of The Methodist Hospital in the Texas Medical Center being treated for complications related to his bronchitis," Bush's office said in a statement Thursday. "He is in stable condition, and is expected to be released within the next 72 hours."
McGrath said the hospital is being "extra cautious" given the former president's age.
Bush was admitted last Friday. He was visited Sunday by his son, former President George W. Bush, and his wife, Laura.
The older Bush and his wife, Barbara, make their winter home in Houston and spend summers in Kennebunkport, Maine.
He was seen a few weeks ago attending a Houston Texans NFL game, something he does frequently.
The former president suffers from a form of Parkinson's disease that has forced him to use a wheelchair or motorized scooter to get around.
The Associated Press contributed to this report.