READING the latest headline of a woman claiming to have the biggest breasts in Britain Tianna Moon can’t help but roll her eyes.
For she believes her boobs, which are now a size 32OO, are deserving of the title and they are set to get even bigger.
Tianna Moon says she has Britain’s biggest boobs at 32OO Credit: SWNS
She says they are larger than people who have claimed to have the biggest Credit: Jam Press/@bigtianna_
Tianna Moon, as she’s known online, suffers from a rare condition called .
It involves the rapid and excessive growth of breast tissue; which the 30-year-old only found out about last year while taking skinny jab, .
Since then, her chest has increased from a size 38M to 34NN and in less than a month, it’s now measuring a cup size 32OO.
Her breasts are larger than who claims to have the biggest breasts in Britain with size 34M and the UK’s largest, , who sports a 30M cup.
Melissa Ashcroft has 36M breasts and believed that hers were largest Credit: SWNS
Summer Roberts was also sure that she boasted the largest chest at 30M Credit: instagram.com/scotchdolly
And while the condition is painful – with the model fearing how much more they’ll grow – she’s hoping to find a silver living in the situation.
“My breasts are much bigger than those claiming the title,” Tianna, from East Anglia, says.
“I’m running out of alphabet at this point.
“I am genuine; unlike a lot of other people claiming the title.
Tianna’s large chest is caused by a condition called gigantomastia Credit: Jam Press/@bigtianna_
She says that she hopes that her breasts stop growing one day Credit: Jam Press/@bigtianna_
“Many of those who claim to have the biggest breasts involve cosmetic enhancement or rely on US alone.
“My situation is different as my chest growth is entirely natural.
“I just let my boobs do what they want.
“Although I do hope they stop at some point.
What is gigantomastia?
Gigantomastia is a rare condition that causes excessive breast growth.
The exact cause isn’t known and it can occur randomly, during puberty, pregnancy, or after taking certain medications.
The breast growth can occur over the course of a few years, but there have been some cases of gigantomastia where a woman’s breasts grew three or more cup sizes within a few days.
Other symptoms include breast pain, posture problems, infections, and back pain.
While gigantomastia is considered a non-cancerous condition, it can be physically disabling if not treated.
In some cases, the condition resolves on its own, but many women with gigantomastia will need to have breast reduction surgery or a mastectomy.
Gigantomastia also goes by other names, including breast hypertrophy and macromastia.
Source: Healthline
“If anybody is bigger than me, I’d love to meet them.”
Growing up, Tianna said her breasts have “always” been on the larger size, which meant she attracted “quite a bit of attention” from people her age and older.
Tianna, from East Anglia, said: “I remember walking home from school as a 13, 14-year-old and it was quite common to have grown men leering at me and honking their horns and stuff.”
She began an OnlyFans career in 2021 after a head injury left her unable to work full-time, claiming to make £10,000 a month from admirers of her fuller bust.
She said: “I might as well try and reap the benefits of my medical condition rather than the negatives.
“After Covid and furlough I decided I wanted to work for myself and be in charge, manage my own schedule and still make money.”
It was a subscriber’s comment that led Tianna to begin tracking her breast size.
“I’ve had a lot of growth since I first started,” she says.
“As they got bigger, it was actually a subscriber who said you need to get remeasured because you are not the size you say you are.
“That’s when I started monitoring them.”
After finding it “odd” her breasts kept growing despite her weight loss in 2024, Tianna did her own research and discovered what gigantomastia was after “stumbling across it” researching a similar condition called macromastia.
Macromastia is a similar but less severe medical condition, in which breasts become enlarged at a more gradual rate.
In July 2025, she went to her GP and explained what she’d been researching.
“He was point blank like ‘this is gigantomastia’,” recalled Tianna. “I got the diagnosis quite early because of the growth not being common with anything else.”
Gigantomastia is a rare condition affecting women, causing rapid and disproportionate breast tissue growth.
People may notice their boobs growing over a few weeks or several years.
It can happen during puberty, pregnancy or from taking medication, but in some cases, it occurs spontaneously and for no reason.
People with gigantomastia tend to have an excess of at least 5lbs of breast tissue, which equals more than 3 per cent of their total body weight.
The combined weight of Tianna’s breast tissue is estimated to be around four stone, which means a large proportion of the figure on the scales is attributed to her chest.
She says: “Living with the condition has a major impact on everyday life.
“The weight causes ongoing back and shoulder pain.
“Exercise can be difficult as they take up pretty much all my front.
“Things like running and jumping can be risky, since they often smack me in the face.
“And even finding clothes that fit properly can be a challenge.”
And despite their growing size, Tianna chooses to ditch bras as she struggles to find ones to hold her boobs.
“I honestly rarely bother with bras,” she says.
“The UK stops making them at a M-cup and wearing the wrong size can cause a lot of pain.
“Even before I maxed out the sizes, my breasts would often break the wires clean in half.
“Sleeping can be a problem, as I can’t lie on my back due to the weight of my boobs.
“Sometimes I do catch them and pull, which wakes me up.
“It doesn’t really impact my sex life, either.”
Eze Chidiebere Paul
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