Reference
Glossary
Erectile dysfunction medicine runs on terminology that nobody explains to you in a ten-minute appointment. These are the words you will meet, in plain English, each linked to the page that covers it in full.
- Terms defined
- 66
- Categories
- 5
- Cross-linked
- Yes
- Jargon tolerated
- None
Anatomy & physiology
- Cavernosal arteries
- The arteries supplying blood to the erectile tissue. At roughly 1–2 mm across they are much narrower than the coronary arteries, which is why they show vascular disease first.More →
- Cavernous nervesneurovascular bundles
- The parasympathetic nerves that trigger an erection. They run alongside the prostate, which is why prostate surgery so often affects erectile function.More →
- Corpora cavernosacorpus cavernosum
- The two cylinders of spongy erectile tissue running the length of the penis. They do essentially all the work of an erection.More →
- Corpus spongiosum
- The third, smaller cylinder on the underside of the penis carrying the urethra. It stays softer during an erection so ejaculation is not obstructed.More →
- Cyclic GMPcGMP
- The signalling molecule that relaxes smooth muscle in the penis and allows blood in. PDE5 inhibitors work by preventing its breakdown.More →
- Detumescence
- The return to a flaccid state, driven by noradrenaline from the sympathetic nervous system contracting the smooth muscle.More →
- Endothelium
- The single-cell lining of blood vessels, which produces nitric oxide. Endothelial dysfunction is the shared mechanism linking ED with cardiovascular disease.More →
- Ischiocavernosus
- A pelvic floor muscle at the base of the penis that raises internal pressure beyond what blood flow alone achieves. It is trainable.More →
- Nitric oxideNO
- The messenger released by nerve endings and blood vessel lining during arousal. It triggers the cascade that produces an erection.More →
- Nocturnal penile tumescenceNPT · morning wood · morning erections
- Erections occurring during REM sleep, typically three to five a night. Their presence indicates the physical mechanism is intact.More →
- Psychogenic erection
- An erection triggered by thought, sight or arousal in the brain rather than by touch.More →
- Reflexogenic erection
- An erection triggered by direct physical stimulation through a spinal reflex, without needing a signal from the brain. Often preserved after spinal cord injury.More →
- Tunica albuginea
- The tough fibrous sheath around each corpus cavernosum. It is what makes an erection rigid rather than merely swollen, and the structure that scars in Peyronie's disease.More →
- Veno-occlusive mechanismvenous occlusion
- The process by which expanding erectile tissue compresses the outflow veins against the tunica albuginea, trapping blood and producing rigidity. Its failure is venous leak.More →
Conditions & causes
- Atherosclerosis
- Plaque build-up narrowing arteries. Because penile arteries are narrow, it causes symptoms there before the heart or brain.More →
- Autonomic dysreflexia
- A dangerous blood pressure surge triggered by stimulation below a spinal cord injury at or above T6, including sexual activity. Needs a plan agreed in advance.More →
- Autonomic neuropathy
- Damage to the involuntary nerves, commonly from diabetes. It interrupts the signal that starts an erection, which is why tablets work less well.More →
- Benign prostatic hyperplasiaBPH · enlarged prostate
- Non-cancerous prostate enlargement causing urinary symptoms. Daily tadalafil is licensed to treat both BPH and ED.More →
- Erectile dysfunctionED · impotence
- The persistent inability to get or keep an erection firm enough for satisfactory sex. The usual clinical threshold is difficulty on most attempts over about three months.More →
- Hyperprolactinaemiahigh prolactin
- Raised prolactin, which suppresses testosterone production. Causes include medication, underactive thyroid and a benign pituitary tumour.More →
- Hypogonadismlow testosterone · low T
- Deficient testosterone production. Diagnosis requires two low morning blood tests plus matching symptoms.More →
- Metabolic syndrome
- The cluster of central obesity, raised blood pressure, raised glucose and abnormal lipids. Strongly associated with erectile dysfunction.More →
- NAIONnon-arteritic anterior ischaemic optic neuropathy
- Sudden painless vision loss in one eye. A very rare adverse effect associated with PDE5 inhibitors; previous episodes are a contraindication.More →
- Neuropraxia
- Temporary loss of nerve function from stretching or bruising rather than division. It explains why erectile function can recover over 12–24 months after nerve-sparing prostate surgery.More →
- Obstructive sleep apnoeaOSA · sleep apnea
- Repeated airway collapse during sleep. It fragments REM, suppresses testosterone and damages blood vessels — a commonly missed cause of ED.More →
- Performance anxietyspectatoring
- Anxiety about sexual performance that activates the sympathetic nervous system — the exact chemical signal that ends an erection.More →
- Peyronie's disease
- Fibrous scar tissue in the tunica albuginea causing penile curvature, pain and often erectile dysfunction.More →
- Priapism
- An erection lasting more than four hours. A medical emergency — go to an emergency department, as delay risks permanent tissue damage.More →
- Prolactinoma
- A benign pituitary tumour that secretes prolactin. Usually treated with dopamine agonists rather than surgery.More →
- Retrograde ejaculation
- Semen passing backwards into the bladder rather than out. Common after prostate surgery and often mistaken for erectile dysfunction.More →
- Venous leakveno-occlusive dysfunction
- Failure to trap blood in the penis, producing an erection that starts well then fades within a minute or two.More →
Treatments & medication
- Alpha-blocker
- Drugs such as tamsulosin and doxazosin for prostate or blood pressure symptoms. They lower blood pressure, so PDE5 inhibitors need careful dose separation.More →
- Alprostadilprostaglandin E1 · Caverject · Edex · MUSE
- A vasodilator given by penile injection, as a urethral pellet or as a cream. It works directly on the erectile tissue without needing a nerve signal.More →
- AvanafilStendra
- The newest and most selective PDE5 inhibitor, with the fastest onset — as little as 15 minutes — and the highest price.More →
- Clomipheneclomifene
- Raises the body's own testosterone by blocking oestrogen feedback at the pituitary. Fertility-preserving, and used off-label in men.More →
- Constriction ringtension ring · cock ring
- A ring at the base of the penis that slows blood leaving it. Maximum 30 minutes of use.More →
- CYP3A4 inhibitor
- Drugs including ketoconazole, ritonavir and clarithromycin that slow the breakdown of PDE5 inhibitors, raising blood levels and requiring dose reduction.More →
- hCGhuman chorionic gonadotropin
- Stimulates the testicles to produce their own testosterone while preserving sperm production. Used off-label where fertility matters.More →
- Intracavernosal injectionICI · penile injection
- Injection of medication directly into the erectile tissue. Success rates of 70–90%+, including in men for whom tablets failed.More →
- Li-ESWTshockwave therapy · low-intensity extracorporeal shockwave therapy
- Acoustic pressure waves applied to the penis, intended to stimulate new blood vessel growth. Classed as investigational and not FDA-approved for ED.More →
- Nitrates
- Drugs including nitroglycerin and isosorbide, plus recreational 'poppers'. Absolutely contraindicated with any PDE5 inhibitor.More →
- PDE5 inhibitorphosphodiesterase type 5 inhibitor
- The drug class including sildenafil, tadalafil, vardenafil and avanafil. They block the enzyme that breaks down cyclic GMP.More →
- Penile prosthesispenile implant · inflatable penile prosthesis · IPP
- Surgically implanted cylinders that restore rigidity. The highest satisfaction rate of any ED treatment, and irreversible.More →
- Penile rehabilitation
- Using medication, a vacuum device or injections after prostate surgery to keep erectile tissue oxygenated while nerves recover.More →
- Platelet-rich plasmaPRP · P-Shot
- Concentrated platelets from your own blood, injected into the penis. Not FDA-approved for ED, and sham-controlled evidence has not shown clear benefit.More →
- Sensate focus
- A structured programme of graded touching exercises with intercourse initially off the table. Removing the goal removes the performance test.More →
- SildenafilViagra
- The original PDE5 inhibitor. Onset 30–60 minutes, useful window 4–6 hours, and inexpensive as a generic.More →
- TadalafilCialis
- A long-acting PDE5 inhibitor with a useful window up to 36 hours, and the only one with a licensed daily dose.More →
- Testosterone replacement therapyTRT
- Treatment for confirmed testosterone deficiency. It suppresses sperm production, so fertility must be discussed before starting.More →
- Trimixbimix
- A compounded injectable mixture of papaverine, phentolamine and alprostadil. Effective at lower doses of each, so less painful than alprostadil alone.More →
- Vacuum erection deviceVED · penis pump
- A cylinder and pump that draws blood into the penis mechanically, held by a constriction ring. Works independently of nerves and arteries.More →
- VardenafilLevitra · Staxyn
- A PDE5 inhibitor similar in duration to sildenafil. Carries a QT-interval caution that the others do not.More →
Tests & measurements
- Haematocrit
- The proportion of blood made up of red cells. Monitored during testosterone therapy because the treatment can raise it to unsafe levels.More →
- HbA1c
- A blood test reflecting average glucose over about three months. Used to screen for diabetes, a leading cause of ED.More →
- IIEF-5SHIM · Sexual Health Inventory for Men
- A five-question screening questionnaire scoring erectile function from 5 to 25. Describes severity; it is not a diagnosis.More →
- LH and FSHluteinising hormone · follicle-stimulating hormone
- Pituitary hormones measured alongside testosterone. A low testosterone with low or normal LH points upstream to the pituitary rather than the testicles.More →
- Penile duplex Doppler ultrasound
- An ultrasound measuring penile blood flow after an injected vasodilator. Used to distinguish arterial insufficiency from venous leak.More →
Commercial & regulatory
- Bioequivalence
- The standard a generic must meet: the same rate and extent of absorption as the original, within defined limits.More →
- Compounded medication
- A preparation mixed by a pharmacy to a prescription. Legal, but not FDA-approved for that formulation — which covers most chewable ED products and trimix.More →
- De Novo pathway
- An FDA route to market for novel low-to-moderate risk devices with no existing equivalent. Used by some newer topical ED products.More →
- FDA-registered vs FDA-approved
- Registration is an administrative listing by the manufacturer. Approval or clearance means the FDA has actually evaluated the product. Marketing frequently blurs the two.More →
- Formulary
- The list of drugs a plan or pharmacy covers or stocks. ED medication is excluded from many US formularies entirely.More →
- Sponsored linkaffiliate link · rel=sponsored
- A monetised link. FTC guidance requires clear disclosure before the reader clicks, and the rel attribute signals the paid relationship to search engines.More →
- Step therapy
- An insurance requirement to try cheaper treatments first. Documenting those failures is what unlocks the next step.More →
Looking for something specific? Search the whole site →