Rising to the occasion is a common problem. And, it is often directly related to how effectively blood is able to flow into and out of your penis - and of your sexual organs in general. However, contrary to what most guys think, 'penis problems' usually have very little to do with the penis itself. If you're having a hard time getting it up - or even staying up during your sexcapades, it is often a warning sign for much bigger problems throughout the rest of your body.