Gynecomastia: the complete guide to understanding, hiding and treating it

You have noticed that your chest has changed: a bump under the nipples, an awkward outline under a fitted T-shirt, maybe some tenderness when you touch it. You are neither alone nor “weird”. Gynecomastia is one of the most common physical traits in men, and one of the least talked about. This guide covers the essentials, and each section links to a detailed article if you want to go further.

What is gynecomastia?

The word comes from the Greek gyne (woman) and mastos (breast). It means an enlargement of the breast gland in a man. Every man has a small amount of breast gland behind the areola. In gynecomastia, this tissue grows and forms a firm, rubbery disc centred under the nipple, which you can feel between your fingers.

Two points are essential:

• it is benign: it is not cancer and does not turn into cancer;
• it is different from simple excess fat, known as pseudogynecomastia or lipomastia. This distinction shapes everything else, because the solutions are not the same.

How many men are affected?

Far more than you might think. Prevalence varies with age, with three well-described peaks:

These figures, from the dermatology and endocrinology literature, include many discreet cases only found on examination. Visible, bothersome gynecomastia is less frequent but still very common. Most men who have it tell nobody, not even their doctor.

Why does the chest develop in a man?

Breast tissue, in men as in women, is controlled by two families of hormones:

• oestrogens stimulate the growth of the gland;
• androgens (testosterone first and foremost) hold it back.

Men have small amounts of oestrogen. Some is made directly by the testicles, and some comes from testosterone being converted by an enzyme, aromatase, which is abundant in fat tissue. Gynecomastia appears as soon as the balance tips towards oestrogens: because oestrogens rise, because androgens fall, or because the gland becomes more sensitive to them.

The main causes

• Physiological causes: birth, puberty, ageing. With age, testosterone falls and body fat rises, and so does aromatase.
• Medicines and other substances: some prostate treatments (anti-androgens, finasteride), spironolactone, some antipsychotics, some HIV medicines, some stomach-acid treatments and, above all, anabolic steroids.
• Illnesses: cirrhosis, kidney failure, an overactive thyroid, hypogonadism (testicles producing little testosterone) and, more rarely, tumours of the testicles or adrenal glands.
• No cause found: this applies to about a quarter of men who see a doctor. This is called “idiopathic” gynecomastia.

We cover each of these causes, including the list of medicines involved, in our article on the causes of gynecomastia.

Gland or fat: the question that changes everything

This is the first thing to establish, because it decides what can work:

In practice, many men have a mixed type: a core of gland surrounded by fat. To find out where you stand, take our gland or fat test, then read our article on the difference between gynecomastia and chest fat.

The different grades

Surgeons most often use the Simon classification, which takes into account volume and excess skin:

• Grade I: small increase in volume, no excess skin.
• Grade IIa: moderate increase, no excess skin.
• Grade IIb: moderate increase, with slight excess skin.
• Grade III: large increase, with marked excess skin that makes the chest “droop”.

The grade guides the choice of surgical technique. It also tells you how much compression you will need to hide it day to day.

Should you be worried?

Most of the time, no. But some signs mean you should see a doctor without delay:

These signs are rare and usually have a harmless cause. They still warrant an examination, and sometimes an ultrasound or a mammogram. For full details, read one-sided gynecomastia, pain: when to see a doctor.

Diagnosis: what happens at the appointment

The appointment is simple and quick. The doctor:

1. asks questions: how long, any pain, medicines, supplements or bodybuilding products, alcohol or cannabis use, other symptoms (low libido, tiredness);
2. examines both breasts, gently pinching the area under the areola to feel for a disc of gland;
3. examines the testicles, because a testicular problem can be the cause;
4. depending on the situation, orders blood tests: testosterone, oestradiol, LH, FSH, prolactin, the pregnancy hormone (hCG), thyroid, liver and kidney function;
5. if doubt remains, requests a breast ultrasound, and possibly a mammogram.

In a teenager whose examination is normal, doctors often simply monitor, because spontaneous regression is the rule.

The solutions, from simplest to most radical

1. Hide it from tomorrow morning

A compression shirt or vest worn under your clothes flattens the chest and makes it invisible under a shirt or T-shirt. It is not a treatment: the gland does not shrink. But it is the fastest way to feel at ease again at work, on a night out or at the gym. Our comparison of compression shirts and our size guide help you choose without getting it wrong.

Your clothes themselves also make a big difference: cuts, fabrics, colours and patterns can completely change your silhouette. That is the subject of our guide how to hide gynecomastia with your clothes.

2. Lose the fat, strengthen the chest

If your chest is mostly fat, weight loss and strength training really work. One caveat: you cannot lose fat from one specific spot. You need to lower your overall body fat. Our complete method: losing chest fat.

3. Remove the cause

If a medicine is responsible, the doctor can sometimes replace it. Never stop a treatment on your own. If you take steroids or prohormones, stopping them is the first step (see gynecomastia and bodybuilding). If a hormonal imbalance is found, correcting it may be enough.

4. Medical treatment

When gynecomastia is recent (under a year) and painful, a medicine from the family of selective oestrogen receptor modulators, such as tamoxifen, can partly reverse it. It is used off-label, on prescription. After a year, the tissue becomes fibrous and medicines have almost no effect. Details: treatment without surgery, what works and what doesn’t.

5. Surgery

This is the only permanent treatment for established gynecomastia. It usually combines liposuction for the fat and removal of the gland through a small incision at the edge of the areola. The operation generally takes one to two hours and is often done as a day case. Everything is explained in gynecomastia surgery, cost and NHS funding, and our guide to surgery abroad.

Living with it in the meantime

Gynecomastia is not dangerous, but it can weigh heavily. Some men give up swimming, the beach, sport in changing rooms, certain clothes, sometimes intimacy. If that is your case, know that it is a common and legitimate reaction, not vanity. There are solutions at every stage. Talking to a doctor is often the first step, and it is easier than you might imagine.

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