Doctor I Am 27 I Have Hbsag Positive, I Had

Doctor I am 27 I have hbsag positive, I had no symptoms, I came to know when I went for medical visa at the age of 22...still I am positive. ...recently i cheked my father's medical reports dated Aug 2016. ..In that he s negative to hbsag and positive to hbcab..what does it mean .even my brother is hbsag positive. ...he also has no symptoms. ..two years back I took treatment.... after treatment doctor told there s no problem in ur case even it s positive. ..I am confused