Gynaecomastia — the benign enlargement of male breast tissue — affects far more men than is widely appreciated. Studies suggest that up to 60–70% of adolescent boys experience some degree of gynaecomastia during puberty, whilst around one-third of adult men may be affected at some point in their lives. In older men aged 50 to 80, prevalence can reach 65% in some studies. Despite these figures, many men feel embarrassed and never seek medical advice. This article explores how common gynaecomastia is, what causes it, when to see a GP, and what treatment options are available on the NHS.

How Common Is Gynaecomastia in Men in the UK

Gynaecomastia affects up to 60–70% of adolescent boys during puberty and around one-third of adult men overall, rising to 24–65% in men aged 50 to 80. It is recognised by the NHS and NICE as a common benign breast condition in primary care.

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Gynaecomastia — the benign enlargement of male breast tissue — is considerably more common than many people realise. Studies suggest that up to 60–70% of adolescent boys experience some degree of gynaecomastia during puberty, representing a peak prevalence rather than a lifetime figure; the condition resolves spontaneously in the majority of cases within one to two years. In adult men, prevalence varies depending on the population studied and the diagnostic criteria used, but estimates indicate that around one-third of adult men may be affected at some point in their lives, with higher rates reported in older age groups.

In older men, the condition becomes increasingly prevalent due to age-related hormonal shifts, with some studies reporting rates of 24–65% in men aged 50 to 80. These figures reflect the wide variation in study methodology and diagnostic thresholds rather than a single definitive estimate. The NHS and NICE Clinical Knowledge Summary (CKS) on gynaecomastia recognise it as a common benign breast condition encountered in male patients in primary care.

Despite its prevalence, gynaecomastia remains underreported. Many men feel embarrassed or assume the condition is untreatable, and therefore do not seek medical advice. Raising awareness of how common the condition is can help reduce stigma and encourage men to access appropriate assessment and support when needed.

What Causes Enlarged Breast Tissue in Men

Gynaecomastia results from an imbalance between oestrogen and androgen activity; causes include physiological hormonal changes, medications such as spironolactone and finasteride, underlying conditions including hypogonadism, and anabolic steroid use.

Gynaecomastia results from an imbalance between oestrogen and androgen (testosterone) activity in breast tissue. Although men naturally produce small amounts of oestrogen, when the ratio of oestrogen to testosterone increases — whether through elevated oestrogen, reduced testosterone, or increased sensitivity of breast tissue — glandular proliferation can occur.

The causes are wide-ranging and include:

• Physiological causes: Neonatal gynaecomastia (due to maternal oestrogens), pubertal gynaecomastia, and age-related hormonal changes in older men are all considered normal physiological processes.

• Medications: A significant number of drugs are associated with gynaecomastia. These include spironolactone, cimetidine, digoxin, anti-androgens used in prostate cancer treatment (such as bicalutamide and flutamide), 5-alpha-reductase inhibitors (finasteride and dutasteride), anabolic steroids, certain antiretrovirals (notably efavirenz), ketoconazole, some calcium channel blockers (e.g., verapamil), and some antipsychotics and antidepressants. Prescribing information for individual medicines (available via the BNF and MHRA-approved Summaries of Product Characteristics) lists gynaecomastia as a recognised adverse effect for many of these agents. If you suspect a medicine may be causing or contributing to gynaecomastia, report it to the MHRA via the Yellow Card scheme at yellowcard.mhra.gov.uk or via the Yellow Card app.

• Underlying health conditions: Hypogonadism (including Klinefelter syndrome), hyperthyroidism, chronic liver disease, chronic kidney disease, and adrenal or testicular tumours can all disrupt hormonal balance and contribute to breast tissue enlargement.

• Recreational substances: Anabolic steroids used for bodybuilding and alcohol are recognised contributing factors. Cannabis has also been cited in some reports, though the evidence for a direct causal link remains limited and inconsistent. Men should also be aware that unregulated bodybuilding supplements and prohormone products may contain androgens or oestrogen-like compounds that can affect hormonal balance.

It is important to distinguish true gynaecomastia (glandular tissue proliferation) from pseudogynaecomastia, which refers to fatty tissue accumulation in the chest area without glandular involvement, commonly seen in men with obesity. This distinction has implications for both diagnosis and management.

When to Seek Medical Advice About Gynaecomastia

See your GP if you notice a firm breast lump, nipple discharge, rapid swelling, or asymmetrical enlargement, as male breast cancer must be excluded. NICE NG12 recommends urgent two-week-wait referral for men aged 30 and over with an unexplained breast lump.

Many men with gynaecomastia delay seeking help, either due to embarrassment or uncertainty about whether their symptoms warrant medical attention. However, there are clear circumstances in which a GP consultation is advisable — and some situations that require prompt assessment.

You should contact your GP if you notice:

• A firm or rubbery lump beneath one or both nipples

• Breast swelling that is tender, painful, or increasing in size

• Nipple discharge of any kind

• Asymmetrical breast enlargement, particularly if only one side is affected

• Swelling that develops rapidly or is accompanied by other symptoms such as fatigue, unexplained weight loss, or testicular changes

While the vast majority of gynaecomastia cases are benign, it is essential to rule out male breast cancer, which, although rare (accounting for less than 1% of all breast cancers in the UK), can present similarly.

In line with NICE NG12 (Suspected Cancer: Recognition and Referral), GPs should refer men aged 30 and over with an unexplained breast lump — with or without pain — on an urgent suspected cancer pathway (to be seen within two weeks). For men aged 50 and over, urgent referral is also recommended for unilateral nipple discharge, nipple retraction, or other concerning nipple changes. For men under 30 with an unexplained breast lump, NICE NG12 advises consideration of a non-urgent specialist referral, taking into account the clinical picture. Skin changes suggestive of breast cancer at any age should also prompt urgent referral. Additionally, a palpable testicular mass warrants urgent suspected cancer referral to urology under NICE NG12.

Men who are taking medications known to cause gynaecomastia should not stop their treatment without first speaking to their prescribing clinician. A review of the medication regimen may be appropriate, but this must be balanced against the clinical indication for the drug. Early consultation allows for timely reassurance, investigation where necessary, and access to treatment options.

How Gynaecomastia Is Diagnosed and Assessed

Diagnosis involves clinical history, physical examination, blood tests (including testosterone, LH, FSH, and oestradiol), and breast ultrasound as first-line imaging. Men with suspicious features should be referred for triple assessment via an NHS rapid access breast clinic.

Diagnosis of gynaecomastia begins with a thorough clinical history and physical examination. The GP will typically ask about the onset and duration of symptoms, any associated pain or discharge, current medications (including over-the-counter products, supplements, and recreational drugs), and relevant medical history. A careful examination of the breast tissue, testes, and lymph nodes is performed to help distinguish gynaecomastia from other conditions.

Key investigations may include:

• Blood tests: A morning total testosterone (with sex hormone-binding globulin [SHBG] to allow calculation of free androgen index), LH, FSH, and oestradiol are typically requested. Liver function tests, renal function, and thyroid function tests are also relevant. Serum human chorionic gonadotrophin (hCG) and oestradiol should be measured if a testicular or adrenal tumour is suspected. Prolactin testing is reserved for men with galactorrhoea or other features suggesting hyperprolactinaemia.

• Imaging: In men, breast ultrasound is generally the first-line imaging investigation, as it is well-suited to distinguishing glandular from fatty tissue and identifying suspicious features. Mammography may be added selectively, particularly when malignancy is suspected or clinical uncertainty remains. Testicular ultrasound is indicated when examination reveals a testicular abnormality or when hCG or oestradiol levels are raised, rather than being performed routinely.

• Rapid access breast clinic / triple assessment: Men with features suspicious of malignancy should be referred to an NHS rapid access breast clinic for triple assessment (clinical examination, imaging, and tissue sampling where indicated), in line with NICE NG12 pathways.

In adolescent boys with typical pubertal gynaecomastia and no concerning features, investigation is often not required, and a watchful waiting approach is appropriate. In adults, the extent of investigation is guided by clinical findings and the likelihood of an underlying cause.

If an underlying condition is identified — such as hypogonadism or hyperthyroidism — treating that condition may lead to resolution of the gynaecomastia. Where no clear cause is found, the condition is classified as idiopathic gynaecomastia. Referral to an endocrinologist, urologist, or breast surgeon may be arranged depending on the clinical picture and local NHS pathways.

Treatment Options Available on the NHS

NHS treatment depends on cause and severity; watchful waiting is first-line for adolescents, whilst tamoxifen and raloxifene are used off-label in adults. Surgery is available but subject to local ICB funding criteria and is not routinely funded for cosmetic reasons alone.

Treatment for gynaecomastia on the NHS depends on the underlying cause, the duration of symptoms, the degree of physical discomfort, and the psychological impact on the individual. In many cases — particularly in adolescents — reassurance and watchful waiting are the first-line approach, as the condition frequently resolves without intervention.

Medical treatments may be considered in certain circumstances:

• Tamoxifen (a selective oestrogen receptor modulator, SERM) and raloxifene have been used to treat gynaecomastia. It is important to note that both agents are used off-label for this indication in the UK; neither is licensed specifically for gynaecomastia. Prescribing should follow shared decision-making, with discussion of potential benefits and risks in line with BNF and MHRA-approved prescribing information. Evidence suggests these agents can reduce breast volume and tenderness, particularly when used during the early, active (proliferative) phase of the condition; they are less effective once fibrosis has established.

• Aromatase inhibitors such as anastrozole have also been explored, though evidence for their use in gynaecomastia remains limited and inconsistent, and they are not routinely prescribed for this indication on the NHS.

• Prophylactic or low-dose therapeutic breast radiotherapy, or prophylactic tamoxifen, may be considered for men at high risk of gynaecomastia from anti-androgen therapy (such as bicalutamide) used in the treatment of prostate cancer. This is addressed in NICE NG131 (Prostate Cancer: Diagnosis and Management) and relevant prescribing information.

If the gynaecomastia is drug-induced, reviewing or discontinuing the causative medication (where clinically safe to do so) may lead to gradual improvement. This should always be done in discussion with the prescribing clinician.

Surgical treatment — typically subcutaneous mastectomy or liposuction — may be considered for men with longstanding, fibrotic gynaecomastia that has not responded to medical management and is causing significant psychological distress. However, NHS funding for surgery is subject to local Integrated Care Board (ICB) clinical policies and NHS England Evidence-Based Interventions guidance, and in many areas it is not routinely funded unless there is a demonstrable clinical need. Men seeking surgical correction for cosmetic reasons alone are generally directed towards private providers. The British Association of Plastic, Reconstructive and Aesthetic Surgeons (BAPRAS) provides patient information on what to expect from gynaecomastia surgery, including risks and realistic outcomes.

Living With Gynaecomastia and Finding Support

Gynaecomastia can affect self-esteem and mental wellbeing; men should discuss psychological impact with their GP, who can refer to NHS Talking Therapies. Practical measures include supportive clothing, maintaining a healthy weight, and avoiding anabolic steroids.

For many men, gynaecomastia has a meaningful impact on self-esteem, body image, and mental wellbeing. Research has shown that affected men may avoid activities such as swimming or exercise, withdraw from intimate relationships, and experience symptoms of anxiety or depression. Acknowledging this psychological dimension is an important part of holistic care.

Practical strategies that some men find helpful include:

• Wearing well-fitted, supportive clothing or compression vests to reduce the visual appearance of breast enlargement

• Maintaining a healthy weight, as excess body fat can worsen the appearance of the chest and contribute to pseudogynaecomastia

• Regular physical activity, particularly resistance training, which can improve chest muscle tone and overall body composition — though exercise alone will not reduce glandular tissue

• Avoiding anabolic steroids, prohormone supplements, and unregulated bodybuilding products, as these may contain androgens or oestrogen-like compounds that can cause or worsen gynaecomastia

Men experiencing significant psychological distress related to gynaecomastia should be encouraged to discuss this openly with their GP. Referral to a talking therapies service (such as NHS Talking Therapies, which offers self-referral in many areas) may be appropriate for those experiencing anxiety or low mood. Where body dysmorphic disorder is suspected, GP assessment and onward referral to appropriate mental health services is recommended.

Online communities and patient forums can provide peer support, though men should be cautious about unregulated advice regarding supplements or treatments. Reputable sources of information include the NHS website (search 'breast enlargement in men'), NICE patient information resources, and BAPRAS for those exploring surgical options. Speaking openly with a healthcare professional remains the most important first step towards effective management and improved quality of life.

Frequently Asked Questions