Psychologic causes
Young age with abrupt onset
Onset associated with specific emotional event
Dysfunction in certain settings while normal function in others
Persistence of nocturnal erections
Previous history of erectile dysfunction with spontaneous improvement
Excessive life stressors—work, relationships
Mental status findings suggestive of depression, psychosis or anxiety disorder
Organic causes
Vasculogenic—arterial
	Persistent interest in sex
	Older age with gradual onset
	Impaired function in all settings
	Presence of chronic disease (particularly diabetes, hypertension)
	Use of prescription/over-the-counter medications associated with erectile dysfunction
	Smoking
	Elevated blood pressure, evidence of peripheral vascular disease (bruits, decreased pulses, skin and hair changes consistent with arterial insufficiency)
Vasculogenic—venous
	Inability to maintain erection once established
	Prior history of priapism
	Local anomalies of the penis
Neurogenic
	History of spinal cord/pelvic trauma or surgery
	Presence of chronic disease (diabetes, alcoholism)
	Presence of neurologic condition (multiple sclerosis, stroke)
	Abnormal neurologic examination of genitals/perineum
Hormonal
	Loss of interest in sexual activity
	Small atrophic testis
	Low testosterone, elevated prolactin