Male sexual health encompasses erectile function, ejaculatory control, libido, and prevention of sexually transmitted infections. Sexual dysfunction increases with age but is not a normal consequence of aging — underlying medical conditions, medications, and psychological factors all contribute.

Sexual health in men involves erectile function, ejaculation, libido, and the prevention of sexually transmitted infections. Source: Unsplash.

Erectile Dysfunction

Erectile dysfunction is the inability to achieve or maintain an erection sufficient for satisfactory sexual performance for 3 months or more. It affects 40% of men at age 40 and 70% at age 70. Complete ED (no erections at all) affects 5% at 40 and 15% at 70. An estimated 50-70% of men with ED do not seek treatment.

Pathophysiology of Erection

Sexual stimulation activates parasympathetic nerves (S2-S4). Non-adrenergic, non-cholinergic neurons and endothelial cells release nitric oxide, which activates guanylate cyclase to produce cGMP. cGMP relaxes corpus cavernosum smooth muscle, allowing blood to fill the corporal sinuses. Expanding sinusoids compress the subtunical venules against the tunica albuginea, trapping blood (veno-occlusive mechanism). Detumescence occurs when cGMP is hydrolyzed by PDE5 and sympathetic tone returns.

Organic vs Psychogenic ED

Organic ED has a gradual onset, poor erections at all times (including morning and masturbatory erections), and is consistent across situations. Risk factors (vascular, neurologic, endocrine, medications) are usually present. Organic ED accounts for 70-80% of cases (often mixed with psychogenic elements). Psychogenic ED has a sudden onset, preserved morning erections (normal nocturnal penile tumescence), good erections with masturbation, and situational variation. It accounts for 10-20% of cases.

Organic Causes

Vascular causes are the most common: atherosclerosis, hypertension, hyperlipidemia, diabetes, and smoking reduce arterial inflow or cause venous leak. Neurologic causes include spinal cord injury, multiple sclerosis, diabetic peripheral neuropathy, Parkinson disease, and stroke. Endocrine causes include hypogonadism, hyperprolactinemia, and thyroid dysfunction. Medications that cause ED include antihypertensives (beta-blockers, thiazides), SSRIs, antipsychotics, antiandrogens, and digoxin. Lifestyle factors include smoking, obesity, alcohol (more than 3 daily drinks), sedentary lifestyle, and sleep apnea. Iatrogenic causes include radical prostatectomy (nerve-sparing vs non-sparing) and pelvic radiation.

⚠ Clinical Correlation

Erectile dysfunction is often an early warning sign of cardiovascular disease. The penile arteries are smaller (1-2 mm diameter) than the coronary arteries (3-4 mm), so atherosclerotic changes manifest as ED 2-5 years before a cardiac event. Any man presenting with ED, especially if he is under 60 and has no known cardiovascular risk factors, should undergo cardiovascular risk assessment including blood pressure measurement, lipid panel, and fasting glucose. Treating ED with lifestyle modification (exercise, weight loss, smoking cessation) not only improves erectile function but also reduces cardiovascular risk.

Evaluation

History and the International Index of Erectile Function (IIEF) questionnaire assess severity, onset, situational factors, risk factors, and psychosocial impact. Physical examination includes testicular size, penile plaques, prostate exam, peripheral pulses, and neurologic exam. The presence of morning erections helps differentiate organic from psychogenic causes. Laboratory evaluation includes fasting glucose or A1c, lipid panel, morning total testosterone (measured twice), and prolactin if testosterone is low.

Treatment

Step 1: Lifestyle modification. Weight loss, exercise (40 minutes per day), smoking cessation, alcohol limitation, and treatment of sleep apnea improve ED in 30-50% of mild cases.

Step 2: Address underlying conditions. Optimize diabetes, hypertension, and lipids. Replace testosterone if hypogonadism is present. Change offending medications when possible.

Step 3: PDE5 inhibitors. These oral medications inhibit PDE5, preventing cGMP breakdown and enhancing the natural erectile response to sexual stimulation. They require sexual arousal to work. Sildenafil (Viagra) takes 30-60 minutes to work and lasts 4-6 hours. High-fat meals delay absorption. Tadalafil (Cialis) takes 30-60 minutes and lasts 24-36 hours (or can be taken daily at 5 mg for continuous readiness). Food does not affect absorption. Vardenafil (Levitra) is similar to sildenafil. Avanafil (Stendra) works in 15-30 minutes and lasts 4-6 hours. All PDE5 inhibitors are contraindicated with nitrate use (any form — nitroglycerin, isosorbide) as this combination can cause profound hypotension. They should be used cautiously with alpha-blockers.

Step 4: Second-line therapy. Intraurethral alprostadil suppository or intracavernosal injection (alprostadil, alone or in combination with papaverine and phentolamine as bimix or trimix) works in 70-85% of men.

Step 5: Vacuum erection device. A negative pressure device draws blood into the penis, and a constriction ring at the base maintains the erection.

Step 6: Penile prosthesis. Inflatable (3-piece) or malleable (semi-rigid) implants achieve over 95% satisfaction.

⚠ Caution

It cannot be overstated: PDE5 inhibitors combined with any form of nitrate (nitroglycerin, isosorbide mononitrate/dinitrate, amyl nitrite “poppers”) can cause a life-threatening drop in blood pressure. This interaction is absolute and applies to all PDE5 inhibitors regardless of dose or timing. If a patient develops chest pain after taking a PDE5 inhibitor, emergency medical providers must be informed so they do not administer nitroglycerin. The window of interaction is at least 24 hours for sildenafil and vardenafil, and up to 48 hours for tadalafil. Nitrates should not be given within this window. In the emergency setting, if a patient with chest pain has taken a PDE5 inhibitor, alternative antianginal medications (beta-blockers, calcium channel blockers, or aspirin) should be used instead.

Premature Ejaculation

Premature ejaculation is defined by three criteria: an intravaginal ejaculatory latency time (IELT) of less than 1 minute (lifelong) or less than 3 minutes (acquired), a perceived lack of control over ejaculation, and personal distress. Lifelong PE is present from the first sexual experiences and may have a genetic or neurobiological basis (low serotonergic activity). Acquired PE begins after prior normal function and is often caused by ED (the man hurries before losing his erection), prostatitis/chronic pelvic pain syndrome, hypothyroidism, anxiety, or relationship issues.

Treatment

Dapoxetine is a short-acting SSRI approved for PE in many countries (not available in the US). Off-label SSRIs including paroxetine, sertraline, and fluoxetine are used daily or on-demand, increasing IELT 3-8 fold. Clomipramine (a tricyclic antidepressant) is also effective. Topical anesthetics (lidocaine/prilocaine cream or spray) applied 20-30 minutes before sex reduce penile sensitivity and increase IELT 5-8 fold — but may reduce sensation for both partners (condom use can help). Behavioral techniques (stop-start, squeeze technique) require partner cooperation and help the man recognize pre-ejaculatory sensations.

Low Libido (Hypoactive Sexual Desire Disorder)

Persistently deficient or absent sexual fantasies and desire, causing distress, affects 5-15% of men. Causes include low testosterone, hyperprolactinemia, depression, medications (SSRIs, opioids), chronic illness, relationship issues, stress, and fatigue. About 30-40% of men with ED also have low desire. Treatment addresses the underlying cause — testosterone replacement for hypogonadism, dopamine agonists for hyperprolactinemia, and counseling for relationship or psychological factors.

STI Prevention

Sexually transmitted infections are preventable. Consistent and correct condom use (latex or polyurethane) reduces transmission of HIV by 85%, gonorrhea and chlamydia by approximately 50-70%, and herpes, HPV, and syphilis by 30-70%. Pre-exposure prophylaxis (PrEP) for HIV reduces HIV acquisition by over 99% with daily dosing. Post-exposure prophylaxis (PEP) for HIV is over 80% effective when started within 72 hours of high-risk exposure. The HPV vaccine (Gardasil 9) prevents over 90% of vaccine-type HPV infections and genital warts — routine vaccination is recommended at age 11-12 with catch-up through age 26. Hepatitis B and A vaccines are recommended for men who have sex with men and those with multiple partners.

Common STIs in men include: chlamydia (often asymptomatic, treated with azithromycin or doxycycline), gonorrhea (purulent discharge, treated with ceftriaxone), syphilis (painless chancre progressing to rash, treated with penicillin), HIV (managed with antiretroviral therapy), genital herpes (painful vesicular lesions, managed with acyclovir/valacyclovir), HPV/genital warts (treated with cryotherapy or topical agents), and trichomoniasis (treated with metronidazole).

ⓘ Information

The CDC recommends: all sexually active men under 25 should be screened annually for chlamydia and gonorrhea. Men who have sex with men (MSM) should be screened at least annually for chlamydia, gonorrhea (urethral, rectal, pharyngeal), and syphilis — every 3-6 months if high risk. HIV testing should be offered at least once to all men, and annually to high-risk men. HIV-positive MSM should be tested for chlamydia, gonorrhea, and syphilis at each visit. Men taking PrEP should be tested for HIV and STIs every 3 months. One-time hepatitis C screening is recommended for all adults.

Summary

Erectile dysfunction is primarily organic and treatable with lifestyle modification, PDE5 inhibitors, and other therapies — it may signal underlying cardiovascular disease. Premature ejaculation responds to SSRIs, topical anesthetics, and behavioral techniques. Low libido often reflects hormonal or psychological issues. STI prevention requires consistent condom use, vaccination (HPV, hepatitis B), PrEP for HIV when indicated, and regular screening per CDC guidelines.