Erectile Dysfunction
Differential Diagnosis
Common Diagnoses
- Excessive Alcohol Intake
- Relationship Dysfunction
- Vascular: Arterial Insufficiency (Arteriopathy) or Excessive Venous Drainage
- Iatrogenic (e.g. Prostatic Cancer Treatments, Hypotensives, some Antidepressants)
- Anxiety
- Depression
Occasional Diagnoses
- Testosterone Deficiency (May be Primary or Secondary)
- Diabetic Autonomic Neuropathy
- Trauma: Pelvic or Spinal Fracture, Trauma to Penis, Post-TURP
- Anatomical: Phimosis, Tight Frenulum
- Excessive Cigarette Smoking
- Peyronie’s Disease
- Drug Abuse (e.g. Heroin, Amphetamines)
Rare Diagnoses
- Fetishism (Erection only Possible with Unusual Stimuli)
- Spinal Cord Compression: Tumour
- Thrombosis of a Corpus Cavernosum
- Neurological: Tabes Dorsalis, Multiple Sclerosis
Ready Reckoner
Key distinguishing features of the most common diagnoses
Depression/ Anxiety | Alcohol | Relationship Dysfunction | Vascular | Drugs | |
---|---|---|---|---|---|
TATT/sleep Problem | Yes | Possible | Possible | No | No |
Occasional Only | Possible | No | Yes | No | No |
Full Morning Erection | Yes | No | Yes | No | No |
Reduced Foot Pulses | No | No | No | Yes | No |
Taking Medication | Possible | No | No | No | Yes |
Possible Investigations
Likely:Urinalysis.
Possible:Blood sugar or HbA1c, FBC, LFT, endocrine assays (testosterone, prolactin, FSH/ LH, TSH), cholesterol, PSA.
Small Print:Doppler flow studies, angiography, intracorporeal prostaglandin injection test, MRI scanning – all likely to be specialist initiated.
- Urinalysis: An essential easy screen for undiagnosed diabetes.
- Blood sugar or HbA1c: To confirm diabetes.
- FBC and LFT possibly helpful in alcohol excess (raised MCV and possible LFT abnormalities).
- Testosterone levels reduced in primary or secondary hypogonadism. Prolactin, FSH/LH and TSH check pituitary function. Erectile dysfunction may be a sign of cardiovascular disease – so in certain patients a cholesterol level would be warranted.
- The link between prostate cancer and erectile dysfunction is far from clear. Some guidelines recommend PSA in this situation to assess for possible prostate cancer; judge each case on its merits and according to other symptoms and the man’s wishes.
- Doppler flow studies of superficial and deep penile arterial flow assess arterial sufficiency. Angiography may be necessary if symptoms suggest significant lower limb arterial insufficiency associated with impotence.
- Intracorporeal prostaglandin injection test: Immediate and prolonged response indicates neurological problems. Good initial response with rapid failure indicates excessive venous drainage.
- Possible neurological causes will occasionally require further investigation (e.g. MRI scanning for cord lesions or MS).
Top Tips
- Establish whether the patient can get an erection at any time (e.g. early morning). If he can, then the cause is unlikely to be organic. Take a positive approach – many psychological causes are transient.
- Don’t be too quick to diagnose anxiety as the underlying problem. This may be the effect, rather than the cause, of the impotence.
- Erectile dysfunction is often presented as a ‘by the way’ or ‘while I’m here’ symptom. The temptation is to invite the patient to book a further appointment, but bear in mind that this may represent a lost opportunity to help, as he may not return.
- Demonstrate that you are taking the problem seriously – for example, by performing an appropriate examination or by inviting the patient’s partner to attend a subsequent appointment.
Red Flags
- Sudden onset of erectile dysfunction with saddle anaesthesia and sphincter disturbance indicates a cauda equina lesion. Refer urgently.
- An erection which is consistently lost after a predictable period is likely to be organic – probably vascular – in origin.
- Do not forget that alcohol and drug abuse are possible causes. Look in the notes for clues and make specific enquiry, as these problems are unlikely to be volunteered.
- Erectile dysfunction may well be a marker for vascular disease elsewhere. Extend your assessment as appropriate.