Erectile dysfunction
🍆 Erectile Dysfunction (ED) = persistent inability to achieve or maintain an erection sufficient for satisfactory sexual performance.
It is common, impacts quality of life, and is often an early marker of systemic vascular disease.
📖 Definition
- ED = difficulty obtaining or maintaining an erection until completion of sexual activity, present ≥3 months.
- Differentiate from decreased libido 🔽, ejaculatory disorders 💦, and infertility 🧬.
🧬 Physiology & Pathophysiology
- Normal erection requires:
- 🧠 Neural input: Parasympathetic S2–S4 → nitric oxide → smooth muscle relaxation.
- 🩸 Vascular inflow: Cavernosal artery dilation → ↑ blood filling.
- 🚧 Venous occlusion: Blood trapped within corpora cavernosa.
- 💪 Hormones: Adequate testosterone.
- ED results from disruption in one or more: vascular (HTN, atherosclerosis), neurogenic (SCI, neuropathy), endocrine (hypogonadism, diabetes), psychogenic (anxiety, depression).
⚠️ Causes of ED
| Category | Examples |
|---|
| 🧠 Psychogenic | Stress, performance anxiety, depression |
| 🩸 Vascular | HTN, atherosclerosis, diabetes, smoking |
| 🧬 Neurological | MS, spinal cord injury, peripheral neuropathy |
| 💉 Endocrine | Hypogonadism, diabetes, thyroid disease |
| 💊 Drugs | SSRIs, TCAs, β-blockers, alcohol, cannabis, cocaine |
| 🔀 Mixed | Combination is very common |
🩺 Clinical Assessment
- 📖 History: Onset (sudden = psychogenic, gradual = organic), nocturnal erections (present = psychogenic), libido, systemic illness, psychiatric history, substance use.
- 👨⚕️ Exam: Secondary sexual characteristics, genital exam (Peyronie’s, testicular size), pulses/BP (vascular disease), neuro exam (neuropathy).
🔬 Investigations
- 🩸 Bloods: Fasting glucose/HbA1c, lipids, testosterone, prolactin, TFTs.
- ❤️ Cardiac risk assessment: ECG, exercise test if high vascular risk.
- 🖥️ Penile Doppler US: specialised, for surgical planning.
💊 Management
- 🌱 Lifestyle: Stop smoking 🚭, reduce alcohol 🍷, weight loss ⚖️, exercise 🏃.
- 🧠 Psychological: CBT, counselling, couples therapy.
- 💊 Pharmacological: PDE5 inhibitors (sildenafil, tadalafil, vardenafil) - enhance NO–cGMP pathway → erection.
❌ Contraindicated with nitrates → severe hypotension.
- 🛠️ Other therapies: Vacuum devices, intracavernosal alprostadil, intraurethral pellets, penile prosthesis (last-line).
📈 Prognosis
- Most men respond to PDE5 inhibitors or devices.
- Addressing lifestyle risks improves erectile & CV health.
- ⚡ ED can precede coronary artery disease by 2–5 years → treat as a vascular warning sign.
✨ Clinical Pearls
- 💡 Sudden ED + normal morning erections → psychogenic.
- ⚡ Gradual ED → organic (usually vascular).
- ❤️ “Angina of the penis” → ED as sentinel for systemic vascular disease.
- ❌ PDE5 inhibitors + nitrates = fatal hypotension.
- 🧑⚕️ Always check testosterone if libido low.
🧑⚕️ Case Examples
Case 1:
👨 A 52-year-old man with type 2 diabetes presents with gradual onset ED. He has reduced morning erections and mild peripheral neuropathy.
🧪 HbA1c 72 mmol/mol, fasting glucose elevated, testosterone normal.
✅ Management: optimise diabetes control, lifestyle changes, start PDE5 inhibitor, screen for cardiovascular risk.
Case 2:
👨 A 40-year-old man reports sudden onset ED after starting sertraline for depression. He still has normal nocturnal/masturbatory erections.
🔎 Exam and testosterone normal.
✅ Management: recognise drug-induced/psychogenic component, discuss alternative antidepressant, consider CBT, PDE5 inhibitor if needed.
📚 References
