Infection and dehydration can cause a cloudy, denser-looking urine. Repeated urine tests as well as the 24-hr voiding test would be reasonable steps for evaluation.
In terms of looking for infection, STD testing for gonorrhea and chlamydia certainly should be done, as well as prostate tests. There are some difficult cases of prostatitis that can cause chronic infection - a transrectal ultrasound can be considered to image the prostate for this possibility. I would also consider blood tests to evaluate the kidney function.
You may want to discuss these options with your urologist.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
Medical Weblog:
kevinmd_b