Organic Causes: Vascular, Neuropathic, Endocrine Factors

Vascular Origin and Endothelial Dysfunction

Vascular etiology is the most preva lent organic cause of erectile dysfunction. An erection is a hemodynamic phenomenon that requires the integration of arterial blood flow and venous occlusion in the corpora cavernosa.

Endothelial dysfunction represents the common pathophysiological substrate in conditions such as hypertension, dyslipidemia, atherosclerosis, and smoking.

Due to the smaller diameter of the cavernous arteries compared to the coronary arteries, erectile vascular insufficiency often manifests as an early marker of systemic cardiovascular disease.

Likewise, alterations in the veno-occlusive mechanism—caused by loss of tissue elasticity or structural damage—prevent the retention of blood flow, leading to what is known as continuous venous leakage.

Neuropathic and Neurobiological Factors

The central and peripheral nervous systems coordinate the transmission of neurobiological stimuli essential for the erectile response.

Neuropathic lesions disrupt parasympathetic and sympathetic autonomic signaling and pudendal somatic innervation.

Prominent central neuropathic causes include multiple sclerosis, cerebrovascular accidents, Parkinson’s disease, and spinal cord injuries.

At the peripheral level, diabetic neuropathy is the most common primary cause, affecting the unmyelinated fibers that innervate the cavernous tissue.

Similarly, radical pelvic surgeries involving the prostate or bladder, as well as mechanical perineal trauma, compromise the integrity of the cavernous plexuses, disrupting the neurological release of nitric oxide and completely abolishing all required physiological vasodilation.

Endocrine and Metabolic Disorders

The endocrine system modulates the erectile response by regulating libido and cavernous hemodynamics.

Hypogonadism, characterized by a deficiency of free and total testosterone, decreases the activity of the enzyme nitric oxide synthase, impairing smooth muscle relaxation.

Hyperprolactinemia inhibits gonadotropin-releasing hormone, reducing testosterone secretion and causing a loss of sexual interest and erectile dysfunction.

Likewise, thyroid dysfunction, hypercortisolemia, and adrenal insufficiency alter steroidogenesis and vascular function.

At the metabolic level, metabolic syndrome and diabetes mellitus accelerate the formation of advanced glycation end products, causing progressive structural damage to the microcirculation and to the local cavernous nerve pathways in the tissue.

Structural and Anatomical Factors

Anatomical abnormalities of the penis mechanically prevent the expansion of the corpora cavernosa and the maintenance of rigidity.

Peyronie’s disease is the most characteristic structural cause, defined by the formation of fibrous plaques in the tunica albuginea with loss of elasticity, penile curvature, and pain during intercourse.

Likewise, direct penile trauma, such as a fracture of the corpus cavernosum, leads to abnormal scarring that alters the tissue architecture.