My mother (age 51 and weight 69 kg) has mild fever (99.5 degree) from last 2 week only in the evening. we has consult the doctor and done test for UTI, CBC and renal function test. All are normal. Can you please advice me, why she is getting mild fever only in the evening....she has also swelling in the right palm and pain in the whole hand, As she has osteoarthritis and walking only with the help of walker with pressure only on the hands. that may be the reason behind the pain and fever. she has to go to washroom 4 times in the night and i had check the diabetes that is normal (125). what is the reason behind it..as UTI reports are sterile.