Most men who come in about erections want a prescription and want the conversation to be over quickly. I understand that. But there is something worth knowing first, because it may matter more than the pill.
The artery size argument
An erection is a vascular event. Sexual stimulation triggers the release of nitric oxide, which raises cyclic GMP, which relaxes the smooth muscle in the erectile bodies and lets blood rush in. As they fill, the expanding tissue compresses the veins against a rigid outer sheath and traps the blood. That trapping is what produces rigidity.
The whole mechanism depends on healthy endothelium, the lining of your blood vessels, being able to produce nitric oxide.
Now consider the plumbing. The arteries supplying the penis are roughly one to two millimeters across. Your coronary arteries are three to four. The same process that narrows arteries narrows all of them, but a given amount of plaque takes a small vessel out of service before a large one.
That is why erectile dysfunction can precede clinically obvious coronary artery disease by two to five years. The complaint that brings a man in about his sex life is frequently the first visible sign of systemic vascular disease.
What this should change
If you are under 60 and your erections have changed without an obvious explanation, that is a cardiovascular risk equivalent. It deserves blood pressure, lipids, a hemoglobin A1c, and an honest conversation about smoking and weight.
I am not saying this to frighten anyone. I am saying it because this is one of the few times in medicine where a symptom people are embarrassed to mention turns out to be an early warning that is genuinely actionable. Men who get worked up at this point often have five years to change the trajectory.
The other causes worth ruling out
Vascular disease is the most common cause but not the only one.
Hormonal. Low testosterone reduces nitric oxide synthase expression and lowers desire, which weakens the central signal that starts the whole cascade. Thyroid disease and elevated prolactin can impair both desire and erectile signaling.
Neurologic. Diabetic neuropathy, spinal cord injury, multiple sclerosis, and pelvic surgery such as radical prostatectomy can damage the nerves involved.
Medications. This one gets missed constantly. Beta blockers, thiazide diuretics, SSRIs, spironolactone, 5-alpha reductase inhibitors, and opioids can all impair erections. A careful medication review is part of any real evaluation, and sometimes the fix is a substitution rather than an addition.
Psychological. Performance anxiety, depression, relationship strain, and stress can cause the problem outright or make an underlying physical problem considerably worse. A useful clue is nocturnal and morning erections. If they are still happening reliably, the hardware is largely intact and the issue is more likely situational.
About the medications
The PDE-5 inhibitors, the familiar ones, do not create erections. They block the enzyme that breaks down cyclic GMP, which amplifies the signal your body is already producing. Sexual stimulation is still required. Men who do not understand this conclude the drug failed when it never had a chance to work.
Two other things worth knowing. Roughly half of apparent treatment failures come down to how the medication was used rather than true non-response, and guidelines suggest four to six attempts at an adequate dose before calling it a failure. Many men are also simply underdosed and give up at the starting dose.
There is one absolute rule. These medications must never be combined with nitrates, including nitroglycerin and the recreational nitrites sometimes called poppers. The combination can drop blood pressure to a life threatening degree. If you take nitrates for chest pain, this class of drug is off the table, and that is not negotiable.
The part that gets skipped
Erectile dysfunction is often the visible end of something broader. Insulin resistance, visceral fat, and metabolic syndrome are among the strongest modifiable risk factors. Excess fat raises aromatase activity, converting testosterone to estradiol, lowers SHBG, promotes inflammation, and directly impairs nitric oxide availability.
Weight loss of even 5 to 10 percent measurably improves erectile function in men with obesity, independent of any medication. Sleep apnea, alcohol, and smoking all pull the same direction.
There is one more piece that clinics tend to ignore. Sexual function happens between two people. If your partner is in perimenopause or menopause and dealing with dryness or pain, treating only you solves half the problem. That is worth raising, and it is worth both of you being evaluated.
When to see a urologist
Most of this can be managed well outside a urology office. Referral makes sense when oral therapy has genuinely failed after proper dosing and adequate trials, after prostate surgery or pelvic radiation, when Peyronie's disease is causing symptoms, or if priapism occurs, which is an emergency.
If you want the broader evaluation rather than just the prescription, that is what I do at Peri Health & Hormones.