Researchers in the UK have found that the shape of a man's urine stream can be analyzed for specific patterns that can be used to predict the maximum flow rate, a value that in turn can be used to diagnose developing urinary problems--including those associated with the prostate. This shape is caused by the surface tension in the urine and the urethra's elliptical shape, the researchers say, and in their tests men were able to self-evaluate their arcs to determine whether their flow rates were indicative of some kind of urinary problem. Considering the majority of men in their 60s and 70s tend to experience some kind of urinary symptom that may be caused by an enlarged prostate, a non-invasive, self-evaluation could go a long way toward catching potentially life-threatening prostate problems early.