Is erectile dysfunction a sign of cancer? This is a common concern for many men experiencing erectile difficulties. Whilst erectile dysfunction (ED) affects approximately half of UK men aged 40–70 to some degree, it is rarely an indicator of cancer. In most cases, ED results from cardiovascular disease, diabetes, psychological factors, or lifestyle issues rather than malignancy. However, certain pelvic cancers—particularly prostate cancer—can occasionally contribute to erectile difficulties, and cancer treatments themselves are a significant cause of ED. Understanding when ED warrants medical assessment is essential for identifying treatable underlying conditions and maintaining overall health.

Understanding Erectile Dysfunction and Its Common Causes

Erectile dysfunction (ED) is the persistent inability to achieve or maintain an erection sufficient for satisfactory sexual activity. It is common in the UK, affecting approximately half of men aged 40–70 to some degree, with prevalence increasing with age, though it can occur at any stage of adult life.

The process of achieving an erection involves a complex interplay between the nervous system, blood vessels, hormones, and psychological factors. When any of these systems are disrupted, ED can result. The most common causes include:

• Cardiovascular disease – conditions affecting blood flow, such as atherosclerosis, hypertension, and high cholesterol

• Diabetes mellitus – which damages both blood vessels and nerves over time

• Psychological factors – including stress, anxiety, depression, and relationship difficulties

• Lifestyle factors – smoking, excessive alcohol consumption, obesity, and lack of physical activity

• Neurological conditions – such as multiple sclerosis, Parkinson's disease, or spinal cord injury

• Hormonal imbalances – particularly low testosterone levels (hypogonadism)

• Medications – certain antihypertensives (e.g. some beta-blockers, thiazides), antidepressants (SSRIs, SNRIs), antipsychotics, spironolactone, opioids, and 5-alpha reductase inhibitors (finasteride, dutasteride) can contribute to ED, though not all agents affect all patients

It is important to recognise that ED is often an early warning sign of cardiovascular disease. Research demonstrates that men with ED have an increased risk of heart attack and stroke, as the smaller blood vessels supplying the penis may show signs of atherosclerosis before larger coronary arteries are affected. For this reason, NICE guidance recommends cardiovascular risk assessment for all men presenting with ED. Whilst ED can be distressing, most cases are related to these common, treatable conditions rather than cancer.

The Link Between Erectile Dysfunction and Cancer

There is no direct causal relationship between erectile dysfunction and cancer in most circumstances. ED itself does not cause cancer, nor does cancer typically present with ED as an initial or isolated symptom. However, certain cancers—particularly those affecting the pelvic region—can occasionally contribute to erectile difficulties through specific mechanisms.

Prostate cancer is the most relevant malignancy when considering ED. The prostate gland sits beneath the bladder and surrounds the urethra, in close proximity to the nerves and blood vessels essential for erectile function. Advanced prostate cancer that has spread locally may, in rare cases, affect these structures. However, it is crucial to emphasise that early-stage prostate cancer—which represents the majority of diagnosed cases in the UK—does not typically cause ED. Most men with prostate cancer have no symptoms at all at diagnosis, with the disease detected through PSA (prostate-specific antigen) testing or investigation of urinary symptoms.

Other pelvic cancers, including bladder cancer (which may present with visible blood in the urine), colorectal cancer (which may cause changes in bowel habit or rectal bleeding), and testicular cancer (which typically presents as a painless testicular lump), may theoretically affect erectile function if they grow large enough to compress or invade nearby neurovascular structures, but this is uncommon and would typically be accompanied by other significant symptoms.

Penile cancer, whilst rare in the UK (affecting approximately 600–700 men annually, around 1–2 per 100,000), may present with visible changes to the penis, a persistent lump or ulcer, discharge, or bleeding rather than ED alone. The key message for patients is that whilst certain cancers can be associated with ED, this is not a typical presentation, and the vast majority of men experiencing erectile difficulties do not have underlying malignancy.

When Erectile Dysfunction May Indicate a Serious Health Condition

Whilst ED is rarely a sign of cancer, it can serve as an important indicator of other serious underlying health conditions that require medical attention. Recognising warning signs is essential for timely diagnosis and management.

Cardiovascular disease is the most significant condition associated with ED. The 'artery size hypothesis' suggests that atherosclerosis affects smaller penile arteries before larger coronary vessels, making ED a potential early warning of heart disease. Men with ED have approximately 1.5 times the risk of cardiovascular events compared to those without. NICE recommends that all men presenting with ED should undergo cardiovascular risk assessment, including blood pressure measurement, lipid profile, HbA1c or fasting glucose, and QRISK calculation.

Diabetes mellitus is both a cause and consequence consideration with ED. Approximately 50% of men with diabetes experience ED, often as an early manifestation of the disease. Undiagnosed diabetes can present with ED alongside other symptoms such as increased thirst, frequent urination, and unexplained weight loss.

Red flag symptoms that warrant urgent medical assessment include:

• Chest pain, breathlessness, or other acute cardiovascular symptoms – call 999 immediately

• Priapism (painful erection lasting more than four hours) – seek emergency assessment immediately

• Suspected cauda equina syndrome – severe back pain with saddle anaesthesia (numbness around the buttocks/perineum), urinary retention or incontinence, and leg weakness – seek emergency assessment immediately

• Sudden onset ED in a previously healthy man, particularly if accompanied by other cardiovascular risk factors

• Perineal or penile trauma followed by ED

• Penile deformity, lumps, or lesions accompanying ED

• Significant urological symptoms including visible blood in urine (haematuria), severe urinary frequency, pain, or complete urinary retention

• Testicular lump or swelling

These presentations require prompt assessment and may necessitate urgent specialist referral to rule out serious pathology, including cancer where indicated by NICE NG12 criteria.

Cancer Treatments That Can Cause Erectile Dysfunction

Cancer treatments represent a significant cause of erectile dysfunction, particularly for malignancies affecting the pelvic region. Understanding these effects helps patients and healthcare professionals anticipate and manage this challenging side effect.

Prostate cancer treatment is the most common cancer-related cause of ED. Radical prostatectomy (surgical removal of the prostate) carries a substantial risk of ED, with rates varying depending on surgical technique (nerve-sparing vs non-nerve-sparing), patient age, and pre-operative erectile function. The operation risks damage to the cavernous nerves that run alongside the prostate and are essential for erections. Nerve-sparing surgical techniques aim to preserve these structures, but success is not guaranteed. Recovery of erectile function, when it occurs, may take 12–24 months or longer.

Radiotherapy for prostate cancer—whether external beam radiotherapy or brachytherapy (radioactive seed implants)—causes ED through gradual damage to blood vessels and nerves. Unlike surgery, where ED is often immediate, radiation-induced ED typically develops progressively over 2–3 years.

Hormone therapy (androgen deprivation therapy) used for prostate cancer significantly reduces testosterone levels, leading to decreased libido and ED in the majority of men. This effect persists whilst treatment continues and may take many months to reverse after cessation.

Other pelvic surgeries and radiotherapy for bladder cancer, rectal cancer, or other pelvic malignancies can similarly damage the neurovascular structures responsible for erectile function. Chemotherapy may contribute to ED through fatigue, hormonal effects, and vascular damage, though this is typically less severe than with surgery or radiotherapy.

NICE guidance and UK oncology/urology practice emphasise the importance of discussing sexual function before cancer treatment begins. Penile rehabilitation strategies may include early use of PDE5 inhibitors (such as sildenafil or tadalafil), vacuum erection devices, or intracavernosal injections. These approaches may help maintain penile oxygenation and support sexual activity, though evidence for improved long-term spontaneous erections is mixed.

Important safety note: PDE5 inhibitors are contraindicated in men taking nitrates (e.g. GTN spray, isosorbide mononitrate) or riociguat, and should be used with caution in those taking alpha-blockers or with significant cardiovascular disease. Always follow the Summary of Product Characteristics (SmPC) and discuss with your doctor or specialist.

When to See Your GP About Erectile Dysfunction

Seeking medical advice for erectile dysfunction is important, both for addressing the condition itself and for identifying any underlying health issues. Many men delay consultation due to embarrassment, but ED is a common medical problem that GPs are well-equipped to assess and manage.

You should arrange a routine GP appointment if:

• You have persistent difficulty achieving or maintaining erections for more than three months

• ED is affecting your quality of life, relationships, or psychological wellbeing

• You have not had recent health checks for cardiovascular risk factors

• You are taking medications that might contribute to ED and wish to discuss alternatives

• You would like to explore treatment options

You should seek urgent medical attention if:

• Call 999 if you develop chest pain, severe breathlessness, or other acute cardiovascular symptoms alongside ED

• Seek emergency assessment if you have a painful erection lasting more than four hours (priapism)

• Seek emergency assessment if you have severe back pain with saddle anaesthesia (numbness around the buttocks/perineum), urinary retention or incontinence, and leg weakness (possible cauda equina syndrome)

• You notice visible blood in your urine or semen

• You develop significant urinary symptoms such as difficulty passing urine, increased frequency, or pain

• You notice any lumps, lesions, or persistent changes to your penis or testicles

• You experience pain during erections or sexual activity

During your consultation, your GP will typically take a detailed history including cardiovascular risk factors, medications, psychological factors, and relationship issues. Examination may include blood pressure measurement, genital examination if indicated, and cardiovascular assessment. Blood tests commonly include HbA1c or fasting glucose (diabetes screening), lipid profile (cholesterol), and total testosterone levels. Testosterone should be measured in a morning sample and repeated if low; if hypogonadism is confirmed, further tests (LH, FSH, prolactin) may be considered to identify the cause.

NICE guidance supports a stepwise approach to ED management, beginning with lifestyle modification and cardiovascular risk reduction, followed by oral PDE5 inhibitors (such as sildenafil, tadalafil) as first-line pharmacological treatment for most men. Specialist referral to urology may be appropriate for complex cases, treatment-resistant ED, or when urgent cancer referral criteria (NICE NG12) are met. Referral to endocrinology may be indicated for confirmed hypogonadism or hyperprolactinaemia, and psychosexual therapy may be helpful when psychological factors are prominent.

If you experience side effects from any medicine, you can report them via the MHRA Yellow Card Scheme at yellowcard.mhra.gov.uk.

Remember: ED is rarely a sign of cancer, but it is an important health indicator that deserves proper medical assessment. Early consultation enables identification and management of treatable underlying conditions whilst improving sexual function and quality of life.

Frequently Asked Questions