Previously, psychological aspects were considered the only cause of erectile dysfunction. Indeed, this factor is the most prevalent among patients under 40 years of age. However, as recently discovered, after 40, the organic nature of the disease begins to predominate. It is necessary to carefully consider the etiology of the pathology in each specific patient, distinguishing between psychological and organic causes of erectile dysfunction, as the treatment of these two types of the disease potentially differs from each other.

General Classification of Organic Causes

Currently, this type of causes is divided into the following subtypes:

  • Non-endocrine - not related to changes in hormone levels;
    • Vasculogenic - related to blood supply;
    • Neurogenic - related to the innervation of the penis;
    • Iatrogenic - related to the intake of medicinal drugs;
  • Endocrine - a decrease in the level of sex and other hormones.

Non-endocrine Causes

The first organic pathology that comes to mind when mentioning erection disorders is the decrease in sex hormones. However, this is not the most common etiology of this dysfunction; more often, its cause lies in diseases not related to any hormonal disorders.

Vasculogenic

Erection is provided by adequate arterial blood flow to the penis; disruption of blood supply is the most common cause of organic erectile dysfunction. This is due to the high frequency of pathologies that can cause vascular disorders:

  • Increased arterial pressure, leading to decreased elasticity of the artery walls;
  • Long-term cigarette smoking and diabetes - can be the cause of both direct damage to the vascular wall and an increased chance of developing atherosclerosis.

Restriction of blood flow leads not only to insufficient filling of the cavernous sinuses but also to constant ischemia of the smooth muscle cells.

Another vasculogenic cause arises not from insufficient inflow but from gradual venous leakage of blood from the erect penis. It is related to the weakness of the venous vessel walls, which cannot retain a large amount of fluid in the cavernous sinuses due to the following risk factors:

  • Long-term smoking and alcohol abuse;
  • Previous injury to the penis;
  • Venous thrombosis, varicose veins;
  • Obesity, increased cholesterol levels;
  • Diabetes.

Neurogenic

Globally, such etiology of the disease is divided into central and peripheral causes. Central causes, more serious and difficult to treat with classical therapy, are associated with disorders in the structure of the central nervous system (CNS) - in the brain and spinal cord.

Control of the initiation and maintenance of erection is performed by several areas (nuclei). Two of them are located in the hypothalamus and midbrain (parts of the brain), and two more are part of the sympathetic and parasympathetic autonomic nervous system in the spinal cord. Thanks to the complex system of interaction of various nuclei of the central nervous system, adequate contraction of the bulbocavernous and cavernous muscles is ensured. They compress the legs of the cavernous sinuses and lead to the rigidity of the penis (erection).

Depending on the level and severity of the injury, different effects act on erectile function. The most common causes of neurogenic pathology:

  1. Spinal cord injury.

It causes paralysis of the lower limbs and pelvic organs, which also include the genital organs. Depending on the level of damage, the patient may retain reflexogenic, psychogenic, or mixed erections:

  • Reflexogenic erection is provoked by direct stimulation of the genitals with preserved centers in the lumbar section; if the injury is higher, the erection may be sufficient for penetration but insufficient for completing sexual intercourse.
  • Psychogenic erection is provided by visual and auditory stimuli, requiring an intact thoracic section of the spine; otherwise, the erection will be insufficient even for penetration.

Patients with spinal cord injury may retain nocturnal erections.

  1. Multiple sclerosis.

An autoimmune disease of the central nervous system that leads to nerve fiber damage. It can cause several types of erectile dysfunction:

  • Primary - directly related to nerve fiber damage;
  • Secondary - due to deteriorated control over the bladder and intestines, muscle weakness;
  • Tertiary - caused by reduced self-esteem, anxiety about the disease, depression due to prognosis.
  1. Parkinson's disease and multiple system atrophy.

Dopaminergic pathways are affected, leading to reduced erection and decreased arousal ability.

  1. Consequences of a stroke.

Ischemia can occur in any part of the brain.

  1. Peripheral neurological disorders.

Nerve fiber damage can occur both after surgical interventions and as a result of various systemic pathologies. Diabetic neuropathy is the most common – nerve damage due to type 1 or type 2 diabetes.

Iatrogenic

They can be associated with both radical surgeries on the pelvic organs and the intake of certain medications. During surgical interventions, the cavernous nerve (innervating the cavernous or cavernous bodies of the penis, which are its "foundation") or the genital artery may be damaged. Drug-induced erectile dysfunction can arise due to the following medications:

  • Beta-blockers, thiazide diuretics, spironolactone, prescribed for arterial hypertension and heart failure;
  • Digoxin for the treatment of atrial fibrillation;
  • Selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants, benzodiazepines, neuroleptics, and other drugs prescribed for mental illnesses;
  • Antiandrogens as part of the therapy for malignant tumors;
  • 5-alpha-reductase inhibitors, prescribed for benign prostatic hyperplasia;
  • H2-receptor blockers for the treatment of peptic ulcer disease.

Endocrine Causes

In the human body, there are several organs that produce special biologically active substances that regulate many processes in the body - hormones. Any change in their balance affects every system in the body - including the reproductive system.

All animal studies confirm the idea that castration (lowering testosterone levels) causes a rapid drop in intracavernous pressure both due to reduced arterial inflow and due to reduced adequate occlusion (spasm) of veins during erection.

There is also little data dedicated to the role of other hormones in erectile dysfunction. A possible role has been confirmed for:

  • Thyroid hormones;
  • Prolactin;
  • Growth hormone;
  • Insulin-like growth factor-1;
  • Dehydroepiandrosterone;
  • Oxytocin.

Although these factors play a role in the pathophysiology of erection, the prevalence of endocrine erectile dysfunction due to dysfunction of these specific hormones is likely small. After testosterone, prolactin is the most frequently altered hormone in men with sexual dysfunction. Its main effect is to block the secretion of gonadotropins (pituitary hormones regulating the development of the sex glands), causing hypogonadism (insufficient development of the sex organs).

Treatment of Organic Erectile Dysfunction

Since the cause of erectile dysfunction is not related to psychological disorders, psychotherapy for such patients will be ineffective. To alleviate symptoms in patients, a urologist may recommend the following treatment steps:

  • Lifestyle modification, combating excess weight, elevated cholesterol, and lipids;
  • Abstaining from smoking and alcohol consumption;
  • Taking oral medications - phosphodiesterase type 5 inhibitors (PDE-5);
  • Using intraurethral suppositories with prostaglandin E;
  • Applying intracavernous injections with prostaglandin E, papaverine, and phentolamine.

Androgens are considered the main hormonal regulator of the development and physiology of the penis. However, the role of testosterone replacement therapy in erectile dysfunction is controversial due to discrepancies in the results of clinical studies. The growing frequency of erectile dysfunction and the progressive decrease in androgen levels with aging do not necessarily imply a cause-and-effect relationship.

In case of ineffectiveness of conservative therapy for the treatment of organic erectile dysfunction, surgeries are used. These interventions may include:

  • Penile prosthesis implantation;
  • Penile revascularization - has the same principles as bypass surgery for ischemic heart disease, during the operation, different arteries are connected, which provides blood flow bypassing the blocked area with arteriosclerotic plaque, spasm, or thrombus.