I don’t think anyone has ever said, “You know what’s really fun? When my dick doesn’t work the way I’d like it to.”

Nope, erectile dysfunction is one of those that can happen to anyone with a penis at some point or another — but that doesn’t make it suck less. However, sometimes knowing more about how an issue works (or, in this case, doesn’t work) can help you feel a little better about it and — who knows? — maybe even prevent it in the future.

First of all, let’s talk about how erections work. The very first body part involved in making an erection happen is the brain. That’s where you get turned on first, right? You see something, hear something, smell something and your brain sends signals to your penis that you’re aroused.

Once your penis gets the message, two things happen at once: the blood vessels carrying blood into the penis expand, while the ones carrying blood out decrease in size. The blood then fills up the corpora cavernosa — which are the two parallel cylinders in the penis — and the tunica albuginea — which is the fibrous wrap around the penis — keeps the blood from getting out again. The penis expands as it fills with blood and that’s what we call an erection.

There are three main reasons why that system might not be working the way it’s supposed to: psychological impact, physical impact, and nervous system response. Let’s break down all three:

1. Psychological impact

Sex advice columnist and podcaster Dan Savage likes to say that erections are like Tinker Bell — you have to believe in them in order for them to work. So if you’re stressed about your erection not working the way you’d like it to, chances are it’s not going to work the way you’d like to. Additionally, certain mental health conditions — such as depression, anxiety, and stress — can also cause erectile dysfunction.

2. Physical impact

There are also physical reasons why someone might have erectile dysfunction. Any cardiovascular health problems — like heart disease, high cholesterol, or clogged vessels to name just a few — that make it so your blood is flowing the way it’s supposed to can have an effect on erections. Other health problems include diabetes, obesity, metabolic syndrome, Parkinson’s, prostate cancer, Peyronie’s disease, and multiple sclerosis. Also, smoking tobacco can have a negative effect on erections, as can alcoholism, sleep disorders, and some prescription medications.

Another physical possibility for erectile dysfunction is pelvic pain. Men who suffer from pelvic pain are more likely to have erectile dysfunction because getting an erection hurts. If you’re suffering from pelvic pain, consider making an appointment with a pelvic health specialist who can help you get things back on track.

3. Nervous system response

Your nervous system has two main branches: the sympathetic nervous system and the parasympathetic nervous system. The parasympathetic nervous system is what helps you rest. When you’re resting, your body is able to do all of that other important stuff, like salivate, digest food, and get aroused.

The sympathetic nervous system, on the other hand, controls our “fight-or-flight” responses. It’s what kicks into gear when your brain thinks you’re in danger. And when you’re in danger, anything that’s not going to help you get out of danger — like digestion and, yes, sexual arousal — is put on hold. So if your sympathetic nervous system is activated — like if you’re scared or even anxious — your body can’t make an erection.

This information is not intended to substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a healthcare professional with any questions you may have regarding treatment, medications/supplements, or any medical diagnoses. This information is intended for educational purposes only and is in no way to substitute the advice of a licensed healthcare professional.