What causes erectile dysfunction physically ?

Here are ...: Each life event is always a process of lifelong making from its many known/unknown factors, which interact together, and represents the ending result of interaction between genetic factors ; lifestyle; so is ed. Here are: aging, impaired circulation ; nerve connection, low male hormone, many diseases, drugs, surgery/injury, etc. Despite enlisting causes as physical or mental, both are inseparable.

Multi-factorial: Erectile dysfunction can occur as a result of physical changes to the blood flow and nerve input that control erections, or psychological issues that can impact performance, or a combination of both. In a 26 year old male, psychological factors are more common, whereas in older men physiological limitations usually prevail. One way to distinguish the etiology is nocturnal tumescence monitoring.