Former President George H.W. Bush was in a Houston hospital Thursday after being treated for complications related to his bronchitis, his spokesman said.
Bush, 88, has been hospitalized at Houston's Methodist Hospital for six days and has a "lingering cough," spokesman Jim McGrath said. He is listed in stable condition and the condition is not considered life-threatening.
The former president was hospitalized before Thanksgiving for the same issue.
"As you get older, your pulmonary function decreases and it becomes difficult to breathe. And your immune system is not as strong so you are less able to fight off infection," said Dr. Nasiya Ahmed with UT Physicians/Geriatric Medicine.
"It's nothing to take chances with. They just wanted to treat it with stronger medicine and more observation, but they've successfully battled that bronchitis back," McGrath said. "They're just waiting for this cough to dissipate just a little bit further."
His family hopes he will be discharged by the weekend, McGrath said.
Bush's son, former President George W. Bush, has been among his visitors.
Bush has a form of Parkinson's disease that affects his legs and requires him to use a wheelchair. He is the oldest living former president and a World War II veteran.
He was previously hospitalized overnight in 2007 after a fainting spell caused by dehydration and hot weather while golfing in California.
Bush served as president from 1989-1993. He was vice president for two terms under President Ronald Reagan.