File photo - Former President George H.W. Bush
(CNN) -- Former President George H.W. Bush remains in a Houston hospital Thursday after being treated for 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 told CNN.
His family hopes he will be discharged by the weekend, McGrath said.
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.