Erectile dysfunction is the persistent inability to achieve or maintain an erection suitable for sexual activity. Normally, sexual stimulation triggers parasympathetic nerves to release nitric oxide, causing smooth muscle relaxation, increased arterial blood flow to the corpora cavernosa, and venous compression to maintain the erection. Erectile dysfunction can stem from vascular, neurological, hormonal, or psychological factors. Vascular conditions like diabetes, hypertension, smoking, and atherosclerosis impair nitric oxide and cGMP signaling, leading to reduced blood flow and inadequate erectile tissue expansion. PDE5 inhibitors help manage the condition by preventing cGMP breakdown, thereby enhancing smooth muscle relaxation and blood flow during sexual stimulation.