For some months I have experienced a burning when urinating. An urinary analysis indicated nothing i.e. no infection, no blood etc. What might be some other possible causes? Thank you

One simple answer could be that you might not be drinking enough fluids an easy way to tell is to check the color of your urine. If it is clear colored most of the time then you are OK. If it is predominantly an orangey-dark color then you should try to drink more water. Concentrated urine can burn when you urinate. Sometimes sexually transmitted diseases (STDs) can cause burning in the urine, and they might not show on an ordinary urine analysis. If you have any reason to think you may have contracted an STD you should get it checked. The easiest method is to buy a self test kit and it yourself in the privacy of you home. If interested you can check out this link
http://testingkits.testcountry.com/E...h_Assessment/4