Male Sexual Dysfunction
Male sexual dysfunction is dominated by erectile dysfunction (ED), and ED makes sense only if you understand the vascular, nitric-oxide-driven mechanism of erection.
The big picture
Male sexual dysfunction is dominated by erectile dysfunction (ED), and ED makes sense only if you understand the vascular, nitric-oxide-driven mechanism of erection — because the first-line drugs (PDE-5 inhibitors) act precisely on that pathway. ED is also a window into vascular health: it shares risk factors with cardiovascular disease and often precedes it. At the other extreme sits priapism, a prolonged erection that, in its ischaemic form, is an emergency that can destroy erectile tissue.
The framework: the erection pathway (NO → cGMP), ED (causes, the PDE-5 first-line, escalation), and priapism (ischaemic vs non-ischaemic).
Mechanism pathway
Tap any step to see why it happens.
Diagnostic algorithm
Each step answers one question. Tap to expand.
Board traps
Erection = NO → cGMP → smooth-muscle relaxation; PDE-5 degrades cGMP, so PDE-5 inhibitors sustain it.
PDE-5 inhibitors are first-line for ED — contraindicated with nitrates and need sexual stimulation.
ED is a marker of vascular disease (metabolic syndrome, diabetes) — it can precede cardiac events.
Ischaemic (low-flow) priapism is an emergency → fibrosis/impotence if delayed; sickle cell is a classic cause.
Non-ischaemic (high-flow) priapism follows trauma and is less urgent.