Introduction

Erection requires an intact parasympathetic reflex at S2 and S3.
Ejaculation requires an intact sympathetic L1 root.
Mnemonic: Erection & ejaculation = Point & Shoot (Para & Sym)

Aetiology

Organic causes

• Spinal cord or cauda equine disease
• Multiple sclerosis
• Endocrine disease
  • DM
  • Hypogonadism
  • Hyperprolactinaemia
• Generalised vascular disease
• Trauma causing nerve or vascular disease
• Hypertension or hypertensive drugs

Psychological causes

• Depression
• Relationship problems
• Sexual orientation uncertainties

Age-related problems (>50) tend to follow a common vicious circle:

Epidemiology

• ED occurs in 52% of men aged 40-70:
  • 17% have minimal ED
  • 25% have moderate ED
  • 10% have complete ED

Investigations

All patients should have a random plasma glucose or urinalysis for glucose to exclude diabetes. Further tests to consider include:

• Serum testosterone, prolactin, LH, sex hormone binding globulin
• TFTs
• FBC
• LFTs, gamma GT, renal function, fasting lipid profile

Treatment

Anxiety-induced ED is treated using a therapeutic regimen based:

• Sexual history
• A period of abstention for several weeks
• Onset of therapy

Pharmaceutical treatments include

• Phosphodiesterase-5 inhibitors eg. Sildenafil citrate (Viagra), tadalafil, verdenafil
• Sublingual apomorphine
• Intracavernosal injections
• Transurethral alprostadil
• External devices
• Surgery

- See more at: http://almostadoctor.co.uk/content/systems/urology/erectile-dysfunction#sthash.v99zXY0p.dpuf