Ultrasound plays a specific but limited role in assessing erectile dysfunction (ED). Whilst diagnostic penile Doppler ultrasound can evaluate blood flow in selected cases, it is not a routine investigation and does not treat ED. Low-intensity shockwave therapy—sometimes confused with diagnostic ultrasound—is an emerging treatment not currently recommended or funded by the NHS. Most men with ED are effectively managed through lifestyle changes, oral medicines such as sildenafil, and addressing underlying health conditions. This article explains when ultrasound is used in ED assessment, what it involves, and the evidence-based NHS treatments available.

What Is Erectile Dysfunction and How Is It Diagnosed?

Erectile dysfunction (ED) is the persistent inability to achieve or maintain an erection sufficient for satisfactory sexual activity. It is common, affecting up to half of men aged 40–70 in the UK to some degree, and becomes more prevalent with age, though it can occur at any stage of adult life. ED is not simply an inevitable part of ageing—it often signals underlying health conditions that warrant medical attention.

The causes of erectile dysfunction are multifactorial and typically classified as organic (physical), psychogenic (psychological), or mixed. Organic causes include cardiovascular disease, diabetes mellitus, hypertension, hormonal imbalances (particularly low testosterone), neurological disorders, and the side effects of certain medicines. Psychogenic factors encompass anxiety, depression, relationship difficulties, and stress. In many cases, both physical and psychological elements contribute to the condition.

Diagnosis begins with a thorough clinical assessment. Your GP will take a detailed medical and sexual history, including questions about the onset, duration, and severity of symptoms, as well as any associated conditions or medicines. A physical examination may include assessment of cardiovascular health, blood pressure, body mass index (BMI) or waist circumference, genital examination, and evaluation of secondary sexual characteristics. Cardiovascular risk assessment using tools such as QRISK3 is routinely performed.

Blood tests are typically arranged to check for underlying conditions. According to NICE guidance, initial investigations usually include HbA1c or fasting glucose (for diabetes), fasting lipid profile (for cardiovascular risk), and morning total testosterone (ideally measured between 9 and 11 am). If testosterone is low, a repeat test is arranged to confirm the result. Further endocrine tests such as prolactin, luteinising hormone (LH), and follicle-stimulating hormone (FSH) may be considered if hypogonadism is suspected. Thyroid function tests are performed only if clinically indicated.

In selected cases where the diagnosis remains unclear or when vascular causes are suspected—particularly in younger men or those being considered for specific treatments—further investigations such as penile Doppler ultrasound may be warranted. This specialist imaging technique, performed in secondary care or andrology services, provides objective information about blood flow to the penis, helping to distinguish between vascular and non-vascular causes of ED.

How Ultrasound Is Used to Assess Erectile Dysfunction

Penile Doppler ultrasound is a specialised diagnostic imaging technique used to evaluate blood flow within the penile arteries and assess the vascular integrity of erectile tissue. This investigation is not routinely performed for all men with ED but is reserved for specific clinical scenarios in secondary care or specialist andrology services, where detailed vascular assessment will influence management decisions.

The procedure typically involves pharmacological stimulation with an intracavernosal injection of a vasodilator (usually alprostadil) to induce an erection. Following injection, a high-frequency ultrasound probe is used to measure blood flow velocity in the cavernosal arteries during both the flaccid and erect states. The examination assesses several parameters, including peak systolic velocity (PSV), which indicates arterial inflow, and end-diastolic velocity (EDV), which reflects venous outflow and the ability of the penis to trap blood within the erectile tissue.

Key indications for penile Doppler ultrasound include:

• Young men with ED where vascular causes are suspected (e.g., following pelvic trauma or surgery)

• Patients being considered for vascular reconstructive surgery

• Assessment before penile prosthesis implantation

• Evaluation of Peyronie's disease or penile curvature

• Medico-legal cases requiring objective documentation

The investigation can identify arterial insufficiency (reduced blood inflow), venous leak (inability to maintain blood within the erectile chambers), or both. Typical cut-offs include a PSV below 25 cm/s suggesting arterial insufficiency, whilst an EDV above 5 cm/s and/or a resistive index below 0.75 may indicate veno-occlusive dysfunction. However, interpretation requires expertise, as results can be affected by anxiety, technique, individual variation, and the degree of pharmacological response.

The test is performed in specialist settings with facilities to manage complications. It is generally well-tolerated, though some men may experience temporary discomfort, penile bruising at the injection site, or, rarely, prolonged erection. Services performing this investigation must be equipped to recognise and treat priapism promptly should it occur.

Low-Intensity Shockwave Therapy for Erectile Dysfunction

Low-intensity extracorporeal shockwave therapy (Li-ESWT) represents an emerging treatment modality for erectile dysfunction, particularly for men with vasculogenic ED. This non-invasive therapy uses acoustic waves delivered to the penile tissue, theoretically promoting neovascularisation (formation of new blood vessels) and improving blood flow to the erectile tissue. It is important to distinguish this from diagnostic ultrasound—Li-ESWT is a therapeutic intervention, not an imaging technique.

The proposed mechanism of action involves mechanical stimulation of penile tissue, which may trigger the release of angiogenic growth factors, stimulate endothelial cell proliferation, and promote the formation of new blood vessels. Some studies suggest it may also improve endothelial function and reduce chronic inflammation within penile tissue. Treatment protocols typically involve multiple sessions (often 6–12) over several weeks, with acoustic waves applied to different areas of the penis and perineum.

Current evidence and NHS availability: Whilst some clinical trials have shown promising results, the evidence base remains limited and inconsistent. NICE has not issued formal guidance recommending Li-ESWT for erectile dysfunction, and the treatment is not routinely commissioned or available on the NHS. Where NICE has reviewed similar interventional procedures, use has typically been recommended only within research settings or with special clinical governance arrangements.

Li-ESWT is primarily offered through private clinics in the UK. The therapy appears to have a favourable safety profile in studies to date, with reported side effects generally mild and including temporary penile pain, skin redness, or bruising. Men considering this treatment should be aware that it remains investigational, long-term efficacy data are limited, and there is no established link between diagnostic ultrasound and therapeutic benefit for ED. Any decision to pursue Li-ESWT should follow discussion with a urologist or andrologist. It has been best studied in men with mild to moderate vasculogenic ED and should not be considered a replacement for evidence-based first-line treatments.

NHS Treatment Options for Erectile Dysfunction

The NHS provides comprehensive, evidence-based treatment for erectile dysfunction, with management tailored to individual circumstances, underlying causes, and patient preferences. NICE Clinical Knowledge Summary recommends a stepwise approach, beginning with lifestyle modification and progressing through pharmacological and mechanical interventions as needed.

First-line management focuses on addressing modifiable risk factors and underlying conditions:

• Lifestyle modifications: Weight loss if overweight, increased physical activity (at least 150 minutes of moderate exercise weekly), smoking cessation, and reducing alcohol consumption

• Optimising management of chronic conditions: Better control of diabetes, hypertension, and hyperlipidaemia

• Medication review: Identifying and, where possible, switching medicines that may contribute to ED

• Psychological support: Referral for psychosexual counselling when psychological factors are prominent

• Testosterone replacement therapy: For men with confirmed hypogonadism, following appropriate evaluation and monitoring in line with UK guidance

Pharmacological treatment with phosphodiesterase type-5 (PDE5) inhibitors represents the mainstay of ED management. These medicines—sildenafil, tadalafil, vardenafil, and avanafil—work by enhancing the natural erectile response to sexual stimulation. They inhibit the enzyme that breaks down cyclic GMP, allowing smooth muscle relaxation and increased blood flow to the penis.

NHS prescribing: Generic sildenafil can generally be prescribed on the NHS for men with erectile dysfunction. Other PDE5 inhibitors (tadalafil, vardenafil, avanafil) remain subject to Selected List Scheme (SLS) restrictions and are available on the NHS only for men with ED due to specific conditions: diabetes, prostate cancer treatment, severe pelvic injury, kidney transplant, spinal cord injury, spina bifida, poliomyelitis, or multiple sclerosis. Men who do not meet these criteria may need to obtain private prescriptions for non-sildenafil PDE5 inhibitors. Additionally, sildenafil 50 mg (Viagra Connect) is available to purchase from pharmacies without a prescription, subject to pharmacist assessment.

PDE5 inhibitors should be taken as directed, allowing adequate trials (typically at least four to six attempts) and dose titration before concluding they are ineffective. Sildenafil and vardenafil are best taken on an empty stomach or after a light meal, as heavy or high-fat meals can delay absorption. Tadalafil and avanafil are less affected by food.

Important safety information: PDE5 inhibitors are contraindicated in men taking nitrates (due to risk of severe hypotension) or riociguat. They should be used with caution in men taking alpha-blockers, as the combination may cause postural hypotension; if both are needed, the alpha-blocker should be stable before starting a PDE5 inhibitor, and the lowest dose of PDE5 inhibitor should be used initially. These medicines should also be used cautiously in men with cardiovascular disease, and men should be advised to seek immediate medical attention if they experience chest pain during sexual activity.

Common adverse effects include headache, facial flushing, nasal congestion, and dyspepsia. Men should be advised to seek immediate medical attention if they experience an erection lasting more than four hours (priapism), which is a medical emergency requiring urgent treatment to prevent permanent damage.

Second-line treatments available through the NHS include:

• Vacuum erection devices: Mechanical pumps that draw blood into the penis

• Intracavernosal injections: Self-administered alprostadil injections

• Intraurethral therapy: Alprostadil pellets inserted into the urethra

• Topical alprostadil cream (Vitaros): Availability and NHS funding vary by local area

• Penile prosthesis implantation: Surgical option for men who have not responded to other treatments, typically requiring specialist urology referral

Reporting side effects: If you experience a suspected side effect from any medicine for erectile dysfunction, you can report it via the MHRA Yellow Card Scheme at yellowcard.mhra.gov.uk or through the Yellow Card app.

When to See a GP About Erectile Dysfunction

Many men feel embarrassed discussing erectile dysfunction, but seeking medical advice is important both for addressing the condition itself and for identifying potentially serious underlying health problems. You should arrange to see your GP if:

• You experience persistent or recurrent difficulty achieving or maintaining erections sufficient for sexual activity

• Erectile problems are causing distress, anxiety, or relationship difficulties

• You notice a sudden change in erectile function (which may indicate an acute medical problem)

• You have other symptoms alongside ED, such as reduced libido, fatigue, or mood changes

• You have cardiovascular risk factors (diabetes, high blood pressure, high cholesterol, smoking) and develop ED

• You notice penile deformity, curvature, or a palpable plaque (which may suggest Peyronie's disease)

• You have persistent low libido with other features that might suggest hypogonadism or pituitary disease

Erectile dysfunction can be an early warning sign of cardiovascular disease. The blood vessels supplying the penis are smaller than coronary arteries, so atherosclerotic disease may manifest as ED before causing angina or myocardial infarction. Assessment of ED therefore provides an opportunity for cardiovascular risk stratification and preventive intervention.

Seek emergency medical attention (call 999 or attend A&E) if you experience:

• Chest pain, severe breathlessness, or palpitations during sexual activity

• An erection lasting more than four hours (priapism), which requires emergency treatment to prevent permanent damage to the penis

• Sudden onset of ED with acute painful swelling of the penis following trauma or injury (possible penile fracture)

Preparing for your appointment: To help your GP assess your condition effectively, consider noting down when symptoms began, any patterns you have noticed, current medicines and supplements, relevant medical history, and any questions or concerns you wish to discuss. Remember that GPs routinely discuss sexual health and will approach the consultation professionally and confidentially.

Early assessment allows for timely identification of underlying causes, appropriate investigation, and access to effective treatments that can significantly improve quality of life and intimate relationships. Your GP can also provide information about local services, including psychosexual counselling and specialist urology or andrology clinics where appropriate.

Frequently Asked Questions