Gynecomastia is the growth of real breast gland tissue in boys and men, and in most cases it traces back to a change in the balance between estrogen and testosterone [1]. This guide, reviewed by Dr. Vishal Purohit, M.Ch. plastic surgeon at Kalpana Aesthetics in Jaipur, explains the main gynecomastia causes in plain language: normal hormone shifts at certain ages, body fat, underlying health conditions, genetic conditions, and the cases where no clear cause is found.
If you are still learning what gynecomastia is and how it is graded, start with the overview of gynecomastia causes, symptoms and grades. This article goes one step deeper into the question many men ask first: why did this happen to me?
Why can breast tissue grow in a man?
Males and females both have breast glands; in males they are usually not noticeable [2]. Both sexes also make both sex hormones, although testosterone is typically higher in males and estrogen higher in females [2]. Estrogen makes breast tissue grow, while testosterone stops estrogen from making breast tissue grow [2]. When the balance tips towards estrogen, the small male gland can enlarge.
Cleveland Clinic describes gynecomastia as a benign (non-cancerous) increase in breast volume due to an increase in glandular tissue, and notes that it affects over 50% of males at some point in their lives [1]. That makes it a common condition, not a personal failing.
It helps to separate two things that look alike:
- True gynecomastia is growth of the gland itself. Exercise or weight loss will not reduce this gland tissue [2].
- Pseudogynecomastia is a larger chest caused by excess fat [1]. It looks like a general increase in breast size rather than a lump [1].
Many men have a mix of both, which is why the cause and the tissue type are assessed together.
Hormone balance and tissue sensitivity, explained simply
A simple way to picture it: the breast gland listens to two signals. Estrogen says “grow” and testosterone says “hold back” [2]. Gynecomastia can appear when estrogen rises, when testosterone falls, or when the gland reacts more strongly than usual to normal hormone levels.
The two hormones also affect each other. Estrogen suppresses luteinizing hormone (LH), the hormone that tells the testicles to release testosterone, so a rise in estrogen can also pull testosterone down [1]. In other words, an increase in estrogen together with a decrease in testosterone is the most common pattern behind gynecomastia [1].
Tissue sensitivity explains why some men with normal blood reports still have true gland growth. In adolescents, an increase in estradiol, testosterone production that lags behind, and increased tissue sensitivity to normal male levels of estrogen are all possible causes [3]. Surgeons writing in Aesthetic Plastic Surgery note that defective androgen receptors or altered breast sensitivity to estrogen can act just like a distorted estrogen-to-androgen ratio [4]. Researchers studying gynecomastia without a known cause have also proposed that the gland may convert hormone precursors into estrogen within the breast itself, or be oversensitive to a normal blood level of estrogen [5].
Gynecomastia causes at a glance
A review published in American Family Physician grouped the causes of gynecomastia by approximate frequency [3]. These figures come from the published literature, not from Kalpana Aesthetics.
| Cause | Approximate share of cases [3] |
|---|---|
| Physiologic (normal hormone phases: newborn, puberty, older age) | 25% |
| Idiopathic (no cause identified) | 25% |
| Medicines or substances | 10% to 25% |
| Cirrhosis (chronic liver disease) | 8% |
| Primary hypogonadism (testicles make too little testosterone) | 8% |
| Tumours | 3% |
| Secondary hypogonadism | 2% |
| Hyperthyroidism (overactive thyroid) | 2% |
| Chronic kidney insufficiency | 1% |
| Other, including familial gynecomastia, HIV and malnutrition | 6% |
Two points stand out. Half of the cases in this table are either a normal life-stage change or have no identifiable cause [3]. Serious illness accounts for a smaller share, but that is exactly the share a medical assessment is designed to catch.
Age-related changes: newborns, puberty and older men
Physiologic gynecomastia has three age peaks: newborns, adolescents, and men older than 50 years [3].
Newborns
Up to 90 percent of newborn boys have breast tissue that can be felt, because the mother’s estrogen crosses the placenta [3]. It usually settles on its own within four weeks of birth [3]. Estrogen is also present in breast milk, so nursing babies may have a slight rise in estrogen levels [6]. Children whose breast swelling persists after their first birthday should be examined further [3].
Puberty
One-half of adolescent boys experience gynecomastia, typically starting at 13 to 14 years of age [3]. The cause is the normal hormone mix of puberty: estradiol rises while free testosterone is still catching up, and the tissue may be more sensitive to estrogen [3]. Physiological adolescent gynecomastia usually lasts no longer than 6 to 12 months and then regresses, although about 5 to 10% of affected boys have persistent enlargement [5]. Adolescents can also develop non-physiologic gynecomastia from substances, supplements or medicines, or because a genetic condition is unmasked when puberty is delayed [3].
How long to wait, and when surgery becomes a reasonable option for a teenager or young adult, is covered in the guide to age and timing for gynecomastia surgery.
Older men
Falling free testosterone levels may contribute to a final peak of gynecomastia in men older than 50 [3]. A study of hospitalised men estimated that approximately 65 percent of men between 50 and 80 years of age have some degree of gynecomastia [3]. Older men produce less testosterone and carry more body fat than younger men, which can increase estrogen levels [2]. Healthline describes this gradual decline of male hormones over several years, sometimes called andropause, as one reason gynecomastia appears around middle age [6].
Weight, body fat and aromatization
Body weight affects the chest in two different ways.
- Fat fills the chest. Excess fat tissue can enlarge the chest without any gland growth; this is pseudogynecomastia [1].
- Fat tissue makes estrogen. An enzyme called aromatase converts androgen-type steroid hormones into estrogens. In fat tissue, aromatase is found in the fibroblasts scattered between fat cells rather than in mature fat cells, and estrogen produced in fat tissue throughout the body may be enough to raise blood estrogen levels [7]. This conversion process is called aromatization.
So weight gain can push the chest towards both fat and gland enlargement at the same time. A pediatric clinical guide notes that obesity is a significant contributor to pseudogynecomastia, but warns that a common mistake is to attribute all breast enlargement in heavier boys to fat without considering gland tissue [8].
This matters for what you can expect from weight loss. Weight loss may decrease gynecomastia caused by fat, and exercise helps with weight loss; but if the cause is a hormone imbalance, exercise is unlikely to make a difference [1]. In Dr. Vishal Purohit’s practice, the target BMI for gynecomastia surgery is within the normal range. Slightly overweight men may also benefit from surgery without waiting, but he does not operate on obese and massively obese men because the surgical risk is too high and skin may sag after later weight loss, requiring further correction.
Underlying thyroid, liver, kidney and testicular conditions
Gynecomastia can be a sign of a medical condition that needs treatment. These conditions typically have other symptoms as well, not just gynecomastia [1].
Overactive thyroid (hyperthyroidism)
Gynecomastia occurs in 10 to 40 percent of men with hyperthyroidism, although it is rarely the only symptom [3]. Once thyroid levels return to normal, the gynecomastia resolves in one to two months [3].
Liver disease
Liver injury can impair the liver’s breakdown of estrogens and increase sex hormone-binding globulin (SHBG), both of which raise the estrogen effect in the body [3]. Men with alcohol-related liver disease are at particular risk, because plant estrogens in alcoholic drinks and the direct suppression of testosterone production by alcohol further disturb the estrogen-to-testosterone ratio [3].
Kidney failure
Hormone problems are common in men with kidney failure, because uremia suppresses testosterone production and damages the testicles directly [3]. Malnutrition occurs in up to 40 percent of patients with kidney failure and may also contribute [3]. Dialysis improves malnutrition-related gynecomastia, but only a kidney transplant effectively resolves both the nutritional and hormonal causes [3].
Testicular conditions and hormone-producing tumours
When the testicles make too little testosterone (primary hypogonadism), gynecomastia may be the only presenting symptom [3]. Causes listed in the literature include testicular trauma, testicular torsion, viral orchitis and congenital absence of the testicles [3].
Tumours are rare, but they are the reason a full examination matters. Approximately 10 percent of men with testicular tumours present with gynecomastia alone, and in a study of 175 men referred to a breast surgeon for gynecomastia, a testicular tumour was found in 3 percent [3]. Leydig cell tumours, although often benign, are prone to cause gynecomastia because they secrete estradiol [3]. Adrenal tumours and tumours that produce the hormone hCG can disturb the balance in a similar way, and all of these tumours require surgical removal [3].
This is why the doctor’s physical examination may extend beyond the chest to the genitals and abdomen [2]. Which blood tests or scans are useful, and when, is explained in how gynecomastia is diagnosed.
Genetic conditions, and why family history is not a diagnosis
The most widely known genetic cause is Klinefelter syndrome, a chromosomal condition in which the testicles make too little testosterone. One-half of men with Klinefelter syndrome have gynecomastia, and primary hypogonadism should be suspected in any adolescent whose pubertal gynecomastia persists [3]. The diagnosis matters beyond the chest: men with Klinefelter syndrome have a breast cancer risk 16 to 30 times higher than other men [3].
Other inherited or developmental conditions listed in the literature include androgen insensitivity syndrome, 5α-reductase deficiency, Kallmann syndrome and hemochromatosis, as well as familial gynecomastia [3]. Research has also pointed to variations in genes such as CYP19 and CYP17A1 as possible causes [5].
What about a father or brother who had gynecomastia? Family history is one part of a careful history, alongside a timeline of symptoms, past illnesses, medicines, recreational drugs, environmental exposures and any testicular injury or disease [9]. A relative with an enlarged chest is a clue that guides the doctor’s questions. It does not, on its own, explain why your gland has grown, and it does not replace an examination.
In Dr. Vishal Purohit’s practice, diagnosing gynecomastia begins with a clinical examination and direct palpation first, followed by ultrasound or MRI when imaging is needed, while hormone blood tests are ordered only when there are other symptoms of hormonal imbalance. He refers a patient to an endocrinologist only when gynecomastia develops suddenly, well after puberty is complete, or when other symptoms of hormonal imbalance are present.
Medicines, supplements and anabolic steroids
Medicines and substances account for roughly 10 to 25% of gynecomastia cases [3]. If you think a prescribed medicine may be involved, discuss it with the doctor who prescribed it before making any change [10]. In Dr. Vishal Purohit’s practice, protein supplements have no role in increasing or decreasing gynecomastia, though growing chest muscle can push the gland outwards and make it look more prominent. Anabolic steroid use is a separate and important cause in gym-going men; steroid and prohormone users must stop for a minimum of 6 weeks before surgery, though 3 months is preferable. The topic is covered in detail in steroids and gynecomastia.
When a cause may remain unclear
In many cases, the cause of gynecomastia is not known [11]. About a quarter of cases are classed as idiopathic [3]. “Idiopathic” does not mean nothing was looked for; it means the usual assessment did not identify a reason.
Some researchers argue that the label is overused. In one study of men with idiopathic gynecomastia, the authors concluded that many of these men have detectable disturbances, possibly from hormone exposure before birth or from glands that carry more estrogen and progesterone receptors than usual [5].
How long the gland has been present also matters. A US insurer’s coverage policy summarises the literature this way: medicines work best in the early growing phase, while long-standing gynecomastia develops stromal fibrosis (scar-like firm tissue) and responds less to conservative treatment [12]. For people with chronically low testosterone, gynecomastia may not go away without treatment [1].
At Kalpana Aesthetics, all breast tissue removed during gynecomastia surgery is always sent for histopathology.
In Dr. Vishal Purohit’s practice, diagnosing gynecomastia begins with a clinical examination and direct palpation first, followed by ultrasound or MRI when imaging is needed. Hormone blood tests are ordered only when there are other symptoms of hormonal imbalance, and he refers patients to an endocrinologist only when gynecomastia develops suddenly, well after puberty is complete, or when other symptoms of hormonal imbalance are present.
Why the cause matters before treatment
Finding the cause is not only about curiosity; it changes the plan. If a medicine is causing the breast enlargement, stopping it under medical advice can solve the problem; if a disease is causing it, the disease needs treatment; and if these problems are not addressed, the condition can come back after it is treated [11].
When true gland tissue persists, Dr. Vishal Purohit’s approach at Kalpana Aesthetics in Jaipur combines VASER or power liposuction with excision of the gland through an inconspicuous hemi-periareolar incision along the lower half of the areola border. The surgery is done under local anaesthesia or general anaesthesia. Details of grades, technique, recovery and cost are on the page for gynecomastia surgery in Jaipur, and short answers to common questions about causes are collected in the FAQ section on gynecomastia causes and risk factors.
Conclusion
Gynecomastia causes range from normal hormone changes in newborns, teenagers and older men to body fat, thyroid, liver, kidney and testicular conditions, genetic conditions, medicines and steroids. In a sizeable share of men, no single cause is found. Knowing which group you fall into helps decide whether to wait, treat an underlying condition, or consider surgery. Dr. Vishal Purohit, M.Ch. plastic surgeon registered with the Rajasthan Medical Council (RMC Reg. 28041/14185), assesses men with gynecomastia at Kalpana Aesthetics, Jaipur.
This is educational information, not medical advice.
