Doctor I Require Ur Help My Mom Suffering From Fever

Doctor I require ur help my mom suffering from fever from last 5 months. All reports are clear. But from 3-4 days when she done her household work then only had fever 99/100 but in morning & night at had a normal temp. Even doctors not properly diagnose it. One Dr.suggest zevit vitamin b12 capsule for her. She is diabetic also. For diabeties she take triglucofortered medicine.Sir pls help what can I do.