Low Testosterone?

Difficulty getting an erection.
You can have your testosterone levels tested, but doctors will usually just give you one of the standard drugs to try first (Viagra, Cialis). Just masturbating will give you a good idea if the drug is working. There are many other conditions that can cause this, and there are other symptoms of low T (mostly depending on your age), and there are other reasons for not being able to get an erection, but you can discuss all that with your doctor. It would take too many pages to say it all.