Dr. med. Dirk Manski

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Erectile dysfunction: Epidemiology and Etiology

Definition of Erectile Dysfunction

Erectile dysfunction (ED) is the inadequacy of erection for at least six months duration, which prevents satisfactory sexual intercourse in more than 70%.

Synonyms: impotentia coeundi.

Epidemiology of Erectile Dysfunction


The prevalence of erectile dysfunction rises with age. In the Massachusetts male aging study (MMAS), the prevalence rate of ED was 8% (40–49 years), 16% (50–59 years), and 37% (60–69 years) (Johannes et al., 2000).

In Germany, a pronounced age dependency is also observed. But, despite the rising prevalence with age, there is a high sexual activity in each age group (96–71%). The prevalence of erectile dysfunction is 2% (30–39 LJ), 10% (40–49 LJ), 16% (50–59 LJ), 34% (60–69 LJ), 53% (70–79 LJ). Overall, the prevalence was 19%, but only 7% were dissatisfied with their sexuality and wanted a treatment (Braun et al., 2000).

Epidemiological Risk Factors for Erectile Dysfunction

Many lifestyle factors and diseases influence the prevalence of erectile dysfunction (in brackets the relative risk according to Johannes et al (MMAS), 2000):

Diabetes mellitus (RR 1.8):

Diabetes mellitus is the most important risk factor for erectile dysfunction since it leads to macroangiopathy, microangiopathy, and neuropathy.

Cardiac diseases (RR 1.5–1.9):

Patients with coronary artery disease or arterial hypertension have an increased risk for ED. Conversely, erectile dysfunction is a clinical sign and risk factor for (yet unrecognized) peripheral or coronary artery disease.

Smoking (RR 1.2):

Smoking leads to vasoconstriction and smooth muscle contraction; in the long run, smoking promotes arteriosclerosis. In the MMAS study, smoking had only a minor impact on the prevalence of erectile dysfunction, whereas in other studies, smoking was more significant.


Chronic abuse of alcohol harbors the risk of marital problems, hypogonadism, and polyneuropathy, all risk factors for erectile dysfunction.

Etiology (Causes) of Erectile Dysfunction

Psychogenic Causes of Erectile Dysfunction:

Depression, anxiety disorders, psychotic disorders, and psychiatric medication cause or aggravate ED. Various psychological conditions (anxiety, overwork, education, depression, trauma, or decreased self-esteem) lead to sympathetic overactivity during intercourse and, thus, to erectile dysfunction. The mental fixation on erectile dysfunction with above mentioned psychological patterns is also possible with an organic ED. Half of men under 40 years with ED have an exclusively psychogenic cause.

Neurogenic Causes of Erectile Dysfunction

Diseases of the CNS:

CNS lesions disrupt the activation of spinal erection centers and cause erectile dysfunction. Important brain centers for erectile function are: limbic system, hypothalamus (paraventricular nucleus and medial area praeoptica) and thalamus. Lesions of these brain areas are caused by a variety of disorders: cerebral hemorrhages or ischemic stroke, Alzheimer disease, Parkinson disease, tumors or multiple sclerosis.

Spinal diseases:

The vast majority of young men after spinal cord injury have erectile dysfunction. Erectile dysfunction is typical for caudal (lumbar) injuries because injury to the sacral erection center is more likely. Reflexogenic erections with good rigidity may be present after cervical or thoracal injury.

Peripheral nerve lesions:

Diabetes mellitus, vitamin deficiency, alcoholism, pelvic surgery (radical prostatectomy, cystectomy, rectum resection), and pelvic fractures cause injury of the cavernous nerves, leading to ED and degenerative processes with apoptosis of the erectile tissue and shrinking of the penis.


Epilepsy leads to a fivefold increased risk of ED, caused by the disease itself and by the medication.

Hormonal Causes of Erectile Dysfunction

Diabetes mellitus:

Diabetes mellitus damages the peripheral nerves (diabetic neuropathies) and arteries (diabetic angiopathy), causing multifactorial erectile dysfunction.

Late-Onset Hypogonadism:

Testosterone deficiency suppresses sexual interest and nocturnal erections. The standard value of testosterone for older men and the indication for hormone replacement therapy to treat erectile dysfunction are uncertain. Low concentrations of DHEA correlate better than low concentrations of testosterone with the prevalence of erectile dysfunction.


Medication and pituitary tumors are the most common causes of hyperprolactinemia. Hyperprolactinemia causes hypogonadotropic hypogonadism, which leads to male infertility, gynecomastia, and erectile dysfunction.

Hyperthyroidism or hypothyroidism:

Thyroid disorders are rarely the cause of erectile dysfunction.

Cushing Syndrome:

Hypercortisolism affects the gonadal hormone axis in 70%.

Vascular Factors Causing Erectile Dysfunction

Arterial diseases:

A reduced arterial inflow leads to reduced venous compression and, thus, to an insufficient erection (reduced rigidity or premature detumescence). The most common cause for a decreased arterial supply is a peripheral arterial disease (PAD) associated with the usual risk factors (smoking, hypertension, diabetes mellitus, lipid metabolism disorders). Other causes of arterial insufficiency are trauma or pelvic radiation therapy. Conversely, erectile dysfunction is a clinical sign and risk factor for (yet unrecognized) peripheral or coronary artery disease.

Veno-occlusive dysfunction:

Increased venous outflow leads to erectile dysfunction. Causes are too large dimensioned veins (congenital or acquired). Furthermore, cavernosal diseases lead to a diminished venous occlusion during erection and to ED (see next paragraph).

Cavernosal Diseases

Cavernosal diseases cause decreased corpus cavernosum elasticity with inadequate venous compression (veno-occlusive dysfunction) during erection. Numerous diseases of the corpus cavernosum, such as Peyronie disease, fibrosis of the corpus cavernosum (e.g., after priapism), degeneration, dysfunction of the GAP junctions, endothelial dysfunction, abnormal shunt between corpus cavernosum and spongiosum (congenital, traumatic, iatrogenic after surgery due to priapism) lead to ED.

Non-penile causes of ED, such as nerve injury, lead to a remodeling process in the corpus cavernosum as the disease progresses, with a decrease in smooth muscle cells and an increase in connective tissue, which complicates further therapeutic measures by additional veno-occlusive dysfunction. The remodeling process seems to be caused by insufficient oxygenation of the corpus cavernosum due to a lack of erections, leading to apoptosis of smooth muscle cells. Intermittent erections are necessary for sufficient oxygenation of the corpus cavernosum.

BPH and Erectile Dysfunction

Benign prostatic hyperplasia with severe symptoms of obstruction is a risk factor for ED.

Systemic diseases Causing ED:

Diabetes mellitus, chronic or end-stage kidney disease, myocardial infarction, emphysema, obstructive sleep apnea, bowel surgery with stoma, or liver cirrhosis.

Side effects of drug therapy:

Aging and Systemic Diseases

Following factors become more prevalent with age and may cause erectile dysfunction:

Index: 1–9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z


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Johannes u.a. 2000 JOHANNES, C. B. ; ARAUJO, A. B. ; FELDMAN, H. A. ; DERBY, C. A. ; KLEINMAN, K. P. ; MCKINLAY, J. B.: Incidence of erectile dysfunction in men 40 to 69 years old: longitudinal results from the Massachusetts male aging study.
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In: N Engl J Med
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Derouet, H.; Osterhage, J. & Sittinger, H. [Erectile dysfunction. Epidemiology, physiology, etiology, diagnosis and therapy].
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  Deutsche Version: Erektile Dysfunktion