Hello and welcome to HCM. Thank you for your query. The causes for burning during urination and itching around the genitalia are various, but the most common (90 %) cause is an infection (simple urinary tract infection, sexually transmitted infections, etc.). But there are other minor and less commonly encountered conditions that could cause such a presentation, like dehydration, diabetes, etc. I would also like to comment on the urine analysis conducted. There have been many cases, although considered to be a laboratory error, it is quite possible that the laboratory has reported a false-negative report. I would advise you to repeat a urine analysis, but this time at a more reputed diagnostic center. The symptoms usually cause stress in the individual which can result in a change in sexual activity, and can easily result in a less rigid erection, mainly due to stress and anxiety. Which is why I would advise the following: -Please request for a urine analysis from a more reputed laboratory (preferably with an early morning urine sample, which would be most concentrated) -Abstain from sexual intercourse -Drink plenty of water and consult a doctor at the earliest -If the urine reports no abnormalities: glycaemic profile and screening for all sexually transmitted diseases will have to be conducted Please do not stress over this, your sexual life should return back to normal once the diagnosis is made, and the condition is adequately treated. I hope I have succeeded in providing the information you were looking for. Please feel free to write back to me for any further clarifications at: http://doctor.healthcaremagic.com/doctors/dr-shoaib-khan/64581 . I would gladly help you. Best wishes.