Hi , Welcome To HCM & Thanks For Asking Your Query Here I have gone through Your query and will try to provide information you need on it In your age it is common to have this kind of back pain and most of the people experience it at some stage of Their life coming to your pain ...As you said you don t have any problem in urinating means you don t have any Urinary Tract infection or stone most probably it seems like you have muscle sprain or strain in your back which may be caused by prolonged sitting in wrong posture or prolong driving etc. Proper rest , Hot packs , Mild excercise along with anti inflammatory medicines like diclofenac and muscle relaxant like thiocolchicoside can relieve your pain but I would strongly suggest you to visit Your Orthopedic Doctor to rule out any underlying medical condition as back pain can be caused by variety of causes including spinal and neurological problems so have a visit to Orthopedic Dr to further evaluate the issue I hope it help Thanks & Get well Soon