Organic causes of erectile dysfunction in men under 40.

There are a significant number of men under 40 who experience erectile dysfunction (ED). In the past, the vast majority of cases were thought to be psychogenic in nature. Studies have identified organic etiologies in 15-72% of men with ED under 40. Organic etiologies include vascular, neurogenic, Peyronie's disease (PD), medication side effects and endocrinologic sources. Vascular causes are commonly due to focal arterial occlusive disease. Young men with multiple sclerosis, epilepsy and trauma in close proximity to the spinal cord are at increased risk of ED. It is estimated that 8% of men with PD are under 40, with 21% of these individuals experiencing ED. Medications causing ED include antidepressants, NSAIDs and finasteride (Propecia), antiepileptics and neuroleptics. Hormonal sources are uncommon in the young population, however possible etiologies include Klinefelter's syndrome, congenital hypogonadotropic hypogonadism, and acquired hypogonadotropic hypogonadism. The workup of young men with ED should include a thorough history and physical examination. The significant prevalence of vascular etiologies of ED in young men should prompt consideration of nocturnal penile tumescence testing and penile Doppler ultrasound. Treatment options that may improve ED include exercise and oral PDE-5 inhibitors.