( CNN ) The family of boxing legend Muhammad Ali hopes he will be home from the hospital in time for his 73rd birthday on Saturday . Ali , who has Parkinson 's disease , has been in an undisclosed hospital this week getting follow-up care for a urinary tract infection , a spokesman for the family said Thursday . Bob Gunnell said Ali is in stable condition and doctors indicated he would be released Friday . Ali was initially released from the hospital on January 7 after an 18-day stay . Born Cassius Clay , the fighter won an Olympic gold medal as a light-heavyweight at 18 . In 1964 , he became world heavyweight champion in an upset victory against Sonny Liston . Shortly thereafter , he changed his name to Muhammad Ali to reflect his conversion to Islam . The boxer was also known for his protest against the Vietnam War and refusal to be drafted into service because of his religious conviction . He won his first 31 fights before losing to Joe Frazier in a 1971 fight hailed by some boxing experts as one of the greatest matches of all time . He retired from boxing in 1981 as a four-time heavyweight champion and announced his diagnosis with Parkinson 's disease three years later .
Muhammad Ali is getting follow-up care for a urinary tract infection , a spokesman says . The boxer was hospitalized in the early hours of Monday after complaining about abdominal pain and nausea at his home near Las Vegas. The boxing legend was hospitalized for 18 days until he was originally released last week .