What causes erectile dysfunction?

This question sits at the start of the P-Shot conversation, before any treatment is chosen, because the cause shapes everything after it.
Underlying problems, including heart disease, behind erectile dysfunction
my.clevelandclinic.org says that in many cases, erectile dysfunction can be the first symptom of another underlying problem, including heart disease. In those cases, the symptom is not the whole story. It can be the visible end of something else.
Why cause comes before any P-Shot decision
That is why the question of cause belongs ahead of any treatment decision, including a P-Shot decision. A news piece on erectile dysfunction as a possible first sign of heart trouble makes the same link in plain terms.
Treatment options once the cause is checked
Once cause has been looked at, treatment options come next. The Cleveland Clinic guide to the Priapus Shot (P-Shot) covers how that option works, along with its benefits and risks.
A provider who skips the cause question
If a provider offers a treatment without asking what else might be behind the symptom, that is the sign to slow down and ask.