In this guide15 sections
- Key Points
- How Common Is Gyno?
- Why Do the Figures Vary So Much?
- How Many Men Have Gynecomastia at Each Age?
- Is Gyno Normal?
- Does Everyone Have Gyno?
- How Rare Is Severe Gyno?
- Is Gyno Usually on Both Sides?
- What Are the Most Common Causes of Gyno in Men?
- Why Is Gyno Becoming More Common?
- Gyno or Chest Fat? Why It Matters for the Statistics
- When Is Gyno Worth Treating?
- Frequently Asked Questions
- Gynecomastia Surgery at Centre for Surgery
- References
Key Points
- Gyno is very common. Depending on age and how it is measured, studies find palpable breast tissue in roughly a third to two-thirds of men.
- It peaks at three stages of life: in newborn babies, during puberty and from middle age onwards.
- Most newborn and teenage gyno settles on its own. In adults it is often long-standing and small, and only a minority of men seek treatment.
- In most men it affects both sides, and the amount of breast tissue tends to rise with age and body fat.
- Small, painless, long-standing gyno is usually harmless. A new, hard, one-sided or fast-growing lump should always be checked by a GP.
- Gyno that is still there after puberty, or that bothers you, can be treated with gynecomastia surgery once any underlying cause has been ruled out.
If you have noticed a lump or puffiness behind your nipples, you are far from alone. Gynecomastia, often shortened to gyno and known informally as man boobs, is one of the most common findings in the male chest. It is the growth of glandular breast tissue in boys and men, usually caused by a shift in the balance between oestrogen and testosterone.[1] Many men assume they are unusual and never mention it, so the true scale of the condition surprises most people.
This guide sets out how common gyno is at each stage of life, why the figures vary so much between studies, how often it affects one side or both, and when it is worth seeing a doctor. If you are still working out whether you have gland tissue or fat, start with our guide to gyno vs chest fat, and our guide to what gynecomastia feels like describes the lump itself.
How Common Is Gyno?
Very common. The European Academy of Andrology’s clinical guideline puts the prevalence of gynecomastia in adult men at between 32% and 65%, depending on age and the definition used.[2] In other words, somewhere between one in three and two in three men have some detectable breast tissue, and most of them never know it is there.
The figures come from studies in which doctors examined men’s chests and felt for a disc of tissue behind the nipple. In a classic 1979 study of 306 healthy men aged 17 to 58 ↗, palpable breast tissue was found in 36%, rising to 57% in men over 44.[3] In most of them the tissue was 4 cm or less across, and a diameter over 5 cm was unusual.
So when people ask “is gyno common?”, the honest answer is yes, but with an important qualification. Most of it is small, painless and unnoticed. Visible gynecomastia that changes the shape of the chest, the kind that makes men avoid swimming or tight t-shirts, is much less common than the headline figures suggest.
Why Do the Figures Vary So Much?
Different studies report anything from around a third to nearly three-quarters of men, and there are four main reasons for the spread:
- Age. Gyno is far more common in teenagers and older men than in men in their twenties, so the age range studied changes the result.
- Body weight. Heavier men are more likely to have breast tissue, and studies of heavier populations report higher rates.[4]
- Definition. Some studies count any palpable tissue; others only count tissue over 2 cm. The stricter the cut-off, the lower the figure.
- Fat versus gland. Chest fat on its own, called pseudogynecomastia, can look similar but is not true gyno. Studies that rely on appearance rather than examination tend to overcount.
How Many Men Have Gynecomastia at Each Age?
Gynecomastia follows a typical pattern across life, with three peaks: at birth, in puberty and from middle age.[2][1]
| Age group | How common | Usual course |
|---|---|---|
| Newborn babies | Breast buds in most full-term babies, boys and girls | Settles during the first year |
| Boys aged 10 to 16 | About 4 in 10 overall, peaking at about two-thirds around age 14 | Most cases settle within 1 to 3 years |
| Young men aged 18 to 26 | About 4 in 10 in one large study | Long-standing tissue is less likely to shrink |
| Adult men | About a third to two-thirds, depending on age and weight | Often small and stable |
| Men aged 50 to 69 | Up to 7 in 10 | More likely to be linked to medicines, health conditions or weight |
In newborn babies
Small breast buds are normal in newborns. A study of full-term babies found palpable breast nodules in most of them, boys and girls alike, and some babies briefly produce a small amount of milk.[5] The tissue reflects hormones from the mother and the baby’s own hormone activity around birth, and it settles gradually during the first year without any treatment. Breast tissue in a baby boy that is growing, red or still present well beyond the first year should be checked by a GP or health visitor.
In teenage boys
Puberty is the most familiar time for gyno to appear. In a study of 1,855 boys aged 10 to 16 published in JAMA ↗, 38.7% had gynecomastia, and the figure rose to about two-thirds of boys aged 14 to 14½.[6] It usually starts between 13 and 14 as a firm, sometimes tender disc behind one or both nipples.
Most teenage gyno goes away by itself, typically within one to three years, as testosterone levels rise and the hormone balance settles.[2][7] It is less likely to settle if it has lasted more than two years or is still there once puberty has finished. Our guide to teenage gynecomastia explains what helps in the meantime and when to see a GP, and our guide to whether gynecomastia goes away on its own covers the timeline in more detail.
Even mild teenage gyno can be hard to live with. In a Boston study of 47 teenagers with gynecomastia, those affected had lower self-esteem and poorer social functioning and mental health than boys without it, whatever the grade of their gyno.[8]
In young men
Gyno does not disappear entirely after the teenage years. A Greek study of 954 healthy young men aged 18 to 26 found breast tissue over 2 cm in 40.5% of them.[9] Men with gynecomastia in that study were heavier on average and had matured earlier. For many men in this group the tissue is left over from puberty: once it has been present for a few years it becomes more fibrous and is unlikely to shrink. Our guide to the age for gynecomastia surgery covers what this means for treatment in your twenties and beyond.
In men over 50
Gynecomastia becomes common again from middle age. In a study of 214 men in hospital published in the American Journal of Medicine ↗, 65% had palpable breast tissue overall, rising to 72% of those aged 50 to 69.[4] More than 80% of men with a body mass index of 25 or above had it, and the amount of tissue increased with body fat.
Several things contribute in this age group. Testosterone falls gradually with age while body fat, which converts testosterone into oestrogen, tends to rise. Older men are also more likely to take medicines that can cause gyno, such as some heart, prostate and stomach drugs, and to have conditions such as liver or kidney disease.[10][1]
Is Gyno Normal?
In most cases, yes. Given how many men have some breast tissue, a small, soft-to-rubbery disc behind the nipple that has been there for years and is not changing is a normal finding rather than a sign of disease. The authors of the hospital study above concluded that long-standing bilateral gynecomastia is present in most older men and does not need investigating unless it is causing symptoms or has appeared recently.[4]
That does not mean it is never worth checking. The guideline advises assessment if the gyno is new, growing quickly, painful or larger than about 5 cm, if it affects one side only, or if there are other symptoms such as a testicular lump, loss of sex drive or unexplained weight loss.[2][1] A GP can examine you and arrange blood tests to look for a hormonal cause.
Does Everyone Have Gyno?
No. Even at its peaks, a substantial minority of men have no palpable breast tissue at all. It is more accurate to say that gyno is common enough to be considered a normal variation in men, especially during puberty and in later life, rather than something that affects everyone.
How Rare Is Severe Gyno?
Much rarer than mild gyno. Most of the tissue found in population studies is under 4 cm across and causes no visible change.[3] Larger gynecomastia, where the chest looks like a small breast or the skin begins to droop, is far less common. Our guide to the grades of gynecomastia explains how surgeons describe the different sizes, from a puffy nipple to a larger breast with loose skin.
Is Gyno Usually on Both Sides?
Yes. In the large studies, breast tissue was present on both sides in the great majority of men: 85% of the young men in the Greek study and all but 11 of the 214 men in the hospital study.[9][4] One side is often bigger than the other, and in teenagers it frequently starts on one side first. True one-sided gyno is less common and should always be examined, as a one-sided, hard lump is the pattern doctors look out for. Our guide to gyno on one side covers this in detail.
What Are the Most Common Causes of Gyno in Men?
In adults who see a doctor about gyno, the cause is usually one of a few things. A widely cited New England Journal of Medicine review gives the approximate breakdown: persistent pubertal gyno in around a quarter of men, medicines in around 10% to 25%, no identifiable cause in around a quarter, and smaller numbers due to liver disease, low testosterone, thyroid problems, kidney disease and, rarely, tumours.[1]
Medicines and substances linked to gyno include anabolic steroids, some prostate and hair loss treatments, spironolactone, some antidepressants and antipsychotics, and cannabis.[10] Our guide to the causes of gynecomastia explains each of these, and we have separate guides to steroid gyno, finasteride and gynecomastia and cannabis and gynecomastia. Never stop a prescribed medicine without talking to your doctor first.
Why Is Gyno Becoming More Common?
There is no good evidence that the underlying rate of gynecomastia has changed dramatically, but several trends make it more visible and more likely. Rising rates of excess weight increase the amount of oestrogen made in body fat, anabolic steroid and supplement use has spread well beyond competitive bodybuilding, and more men live into the age group where gyno is most common. More men are also aware of the condition and willing to seek help. Our guide to why gynecomastia is becoming more common looks at these factors in more depth.
Gyno or Chest Fat? Why It Matters for the Statistics
Many men who think they have gyno actually have chest fat, and many have a mixture of both. The distinction matters, as fat responds to weight loss while gland tissue does not. Firm, rubbery tissue concentrated under the nipple suggests gland; soft tissue spread evenly across the chest suggests fat. An examination is the only reliable way to tell, which is why the condition is often over- or under-estimated when people judge by appearance alone.[11] Exercise can reduce fat but not gland, as our guide to whether exercise gets rid of gynecomastia explains.
When Is Gyno Worth Treating?
Most gyno does not need any treatment. It is worth seeing a GP if it is new, painful, growing or one-sided, so that any underlying cause can be found and treated. In some men, treating the cause, such as stopping steroids or changing a medicine, allows recent gyno to settle.[2]
Long-standing gyno that has been there for more than a year or two has usually become fibrous and is unlikely to shrink on its own or with medication. If it bothers you, surgery removes the gland tissue, usually combined with liposuction to smooth the surrounding chest. Our guides to non-surgical treatments for gynecomastia and whether gynecomastia surgery is worth it set out the options, and our guide to gynecomastia surgery on the NHS explains when it may be funded.
Frequently Asked Questions
What percentage of men are affected by gynecomastia?
Studies find palpable breast tissue in roughly 32% to 65% of adult men, depending on age, body weight and how gyno is defined. Most of it is small and goes unnoticed.
Is it normal for a 17 year old to have gyno?
Yes. Pubertal gyno is very common and can still be present at 17. Many cases settle by the end of puberty, but gyno that has lasted more than two years is less likely to go away. A GP can check it and advise whether it needs further assessment.
How common is gyno in teenagers?
Very common. In a large study of boys aged 10 to 16, about 4 in 10 had gyno, rising to about two-thirds of boys aged 14. Most cases resolve within one to three years.
How rare is gyno?
Gyno itself is not rare. Visible gyno that changes the shape of the chest is much less common than the small, unnoticed tissue found in examination studies.
Is gyno more common in overweight men?
Yes. Body fat converts testosterone into oestrogen, and studies show both the prevalence and the size of breast tissue rise with body mass index. Slim and muscular men can still have it, though.
Does gyno go away on its own?
Newborn and most teenage gyno settles by itself. In adults, gyno that has been present for more than a year or two has usually become fibrous and rarely shrinks without surgery, although recent gyno caused by a medicine or steroid can improve once the cause is removed.
Can women get gynecomastia?
No. Gynecomastia describes breast tissue growth in boys and men. Breast development in girls and women is normal.
Gynecomastia Surgery at Centre for Surgery
Centre for Surgery treats gynecomastia in adults aged 18 and over. Surgery is performed by GMC-registered plastic surgeons as a day case under TIVA at our Baker Street hospital, rated Good by the Care Quality Commission, and the surgeon who assesses you is the surgeon who performs your operation. Our gynecomastia surgery cost guide sets out the prices, and you can see results in our gynecomastia before and after photos.
Phone: 020 7993 4849 | Email: contact@centreforsurgery.com | Address: 95–97 Baker Street, London W1U 6RN
References
- Braunstein GD. Clinical practice. Gynecomastia. New England Journal of Medicine 2007;357(12):1229–1237. doi:10.1056/NEJMcp070677 ↗
- Kanakis GA, Nordkap L, Bang AK, et al. EAA clinical practice guidelines: gynecomastia evaluation and management. Andrology 2019;7(6):778–793. doi:10.1111/andr.12636 ↗
- Nuttall FQ. Gynecomastia as a physical finding in normal men. Journal of Clinical Endocrinology and Metabolism 1979;48(2):338–340. doi:10.1210/jcem-48-2-338 ↗
- Niewoehner CB, Nuttall FQ. Gynecomastia in a hospitalized male population. American Journal of Medicine 1984;77(4):633–638. doi:10.1016/0002-9343(84)90353-x ↗
- McKiernan JF, Hull D. Breast development in the newborn. Archives of Disease in Childhood 1981;56(7):525–529. doi:10.1136/adc.56.7.525 ↗
- Nydick M, Bustos J, Dale JH, Rawson RW. Gynecomastia in adolescent boys. JAMA 1961;178:449–454. doi:10.1001/jama.1961.03040440001001 ↗
- Soliman AT, De Sanctis V, Yassin M. Management of adolescent gynecomastia: an update. Acta Biomedica 2017;88(2):204–213. doi:10.23750/abm.v88i2.6665 ↗
- Nuzzi LC, Cerrato FE, Erikson CR, et al. Psychosocial impact of adolescent gynecomastia: a prospective case-control study. Plastic and Reconstructive Surgery 2013;131(4):890–896. doi:10.1097/PRS.0b013e3182818ea8 ↗
- Georgiadis E, Papandreou L, Evangelopoulou C, et al. Incidence of gynaecomastia in 954 young males and its relationship to somatometric parameters. Annals of Human Biology 1994;21(6):579–587. doi:10.1080/03014469400003582 ↗
- Deepinder F, Braunstein GD. Drug-induced gynecomastia: an evidence-based review. Expert Opinion on Drug Safety 2012;11(5):779–795. doi:10.1517/14740338.2012.712109 ↗
- Johnson RE, Murad MH. Gynecomastia: pathophysiology, evaluation, and management. Mayo Clinic Proceedings 2009;84(11):1010–1015. doi:10.1016/S0025-6196(11)60671-X ↗
