What Is Gigantomastia

Defined as extremely large breasts due to excessive breast tissue growth, gigantomastia, ‘’breast hypertrophy’’, or ‘’macromastia’’ is a rare, physically, psychologically, and socially disabling condition that: a) only affects females, and b) is often idiopathic (occurs spontaneously). 

Wondering what is defined by ‘’excessive’’, whether gigantomastia is cancerous, preventable or treatable, if you are at risk, and what to do if you are? (and much, much more!) Look no further! This article has you covered! 


As the name suggests, gigantomastia1 or ‘’breast hypertrophy’’, as it is sometimes called, is a rare disease that causes some females to develop gigantic (‘giganto’) or extremely large breasts (‘mastia’).  

Females with gigantomastia have breasts or mammary glands1 that:

  • Contain an extra 5 pounds (or approximately 2.3 kilograms) of breast tissue 
  • Weigh more than 3% of their total body weight 

Despite the breast tissue growing at a faster pace than is normal, gigantomastia is often benign,1 meaning that it rarely develops into breast cancer or spreads around the body. However, the condition can be physically, emotionally, psychologically, and socially disabling, as will be covered shortly. 

People sometimes confuse gigantomastia with macromastia1 and use both terms interchangeably, however, one large difference exists. Whilst females with gigantomastia have excess breast tissue that weighs more than 5 pounds, those with macromastia have less than 5 pounds of excess breast tissue

There are four main types of gigantomastia:

  1. Juvenile gigantomastia: occurs during puberty, hence ‘juvenile’
  2. Gestational gigantomastia: occurs during pregnancy, hence ‘gestational’
  3. Drug-induced gigantomastia (or medication-induced): occurs after taking certain drugs and/or medications
  4. Idiopathic gigantomastia: occurs spontaneously without a known or determined cause. This is the most common type of gigantomastia

Causes of gigantomastia

Unfortunately, at least to date, the exact causes of gigantomastia remain unknown. However, some research scientists believe that certain factors1 may trigger gigantomastia including: 

  • Hormone fluctuations: occurring during pregnancy and/or puberty
  • Certain medications: including penicillamine or bucillamine
  • Certain autoimmune diseases: such as lupus or arthritis 
  • Extreme obesity
  • Genetics (heredity)

Signs and symptoms of gigantomastia

The signs and symptoms of gigantomastia cause physical, emotional, and psychological pain at varying degrees, depending on severity and type

However, the most common signs and symptoms1 of gigantomastia include:

  • Infection, ulceration, or lesions mainly under the breasts
  • Back pain
  • Neck pain
  • Shoulder pain
  • Breast pain (‘mastalgia’)
  • Posture issues 
  • Loss of nipple sensation 
  • Painful and itchy indentations on the skin from bra straps 

Management and treatment for gigantomastia

The management and treatment for gigantomastia depend primarily on the severity of the signs and symptoms and breast size.  

The main current management and treatment options1 for gigantomastia include: 

  1. Medications: a healthcare provider may prescribe any of the following medications to slow down and prevent breast tissue growth:

Typically, medication alone is sufficient to treat mild to moderate gigantomastia. However, in certain cases it may need to be combined with surgery to reap the most benefits. 

  1. Surgery: Two main types of surgery are currently used to treat gigantomastia:
    • Breast reduction surgery (or ‘’reduction mammaplasty’’): As the name suggests, this plastic surgery procedure involves reducing the size of the breasts. A plastic surgeon accomplishes this by making an incision (cut) in breast tissue and removing excess skin, fat, and tissue. The incision is then stitched together and the nipples are realigned to accommodate the new breast tissue. Breast reduction surgery takes a few hours to complete and may require the patient to stay at the hospital overnight. Patients are expected to experience mild pain, swelling, and bruising, at least for the first few days following reduction mammaplasty. To minimise pain and prevent infection, a healthcare provider may prescribe pain relievers and antibiotics, respectively. A follow-up appointment is often scheduled to re-examine the breasts and remove any remaining stitches. 
    • Mastectomy: An extensive surgery, mastectomy involves cutting out and removing the entire breast tissue. It is only performed in cases where the gigantomastia is severe or recurring, and breast reduction surgery or medication is not sufficient to reduce or stop breast tissue growth. Mastectomies carry heavy risks and require a long recovery time, the length of which depends primarily on age, and underlying medical conditions, However, patients typically take over a month to recover from a mastectomy. Therefore, the decision to carry out a mastectomy should not be made lightly and certainly not without consulting a healthcare provider first. 


To offer a diagnosis1 for gigantomastia, a general practitioner (GP), doctor, or healthcare provider will mainly check the patient’s medical history and perform a physical examination. During these tests, the patient will be asked questions about:

  • Breast size, and how it has changed 
  • Symptoms experienced
  • Any medications that have been recently taken 

Further diagnostic tests are often not required to confirm gigantomastia. 


Having excess breast weight puts a lot of strain on the body, and therefore, if untreated, can lead to severe complications1. The complications are not only physical but emotional, psychological, and social too, as listed down below. 

Physical complications of gigantomastia

  • Back pain 
  • Neck pain 
  • Shoulder pain
  • Breast pain
  • Breast asymmetry: resulting in different-sized breasts
  • Difficulty walking, running, and/or exercising: over time. This leads to obesity which, sadly, only exacerbates the symptoms  
  • Difficulty breastfeeding: As a result, this may lead to impaired fetal growth
  • Skin infections, especially around the bra area 
  • Itchy and inflamed skin 
  • Low milk supply, mastitis (breast inflammation and infection), blisters and sores in pregnant women 

Emotional, psychological, and social complications of gigantomastia 

  • Depression 
  • Anxiety
  • Poor body image 
  • Social withdrawal 


How can I prevent gigantomastia?

Unfortunately, because research scientists are uncertain of what causes gigantomastia, it cannot be prevented,1 at least not to date. 

How common is gigantomastia?

Very uncommon.1 Gigantomastia is a rare condition, with only 300 cases reported so far. 

Who is at risk of gigantomastia?

As discussed above, the risk of gigantomastia1 is believed to be highest in women who: 

  • Are either pregnant or going through puberty
  • Have a history of medication use: e.g. penicillamine or bucillamine 
  • Have certain autoimmune conditions: e.g. lupus or arthritis 
  • Are overweight or have extreme obesity 
  • Are genetically predisposed: due to having a family history of gigantomastia 

Nevertheless, it is important to remember that most cases of gigantomastia occur spontaneously (idiopathic) and therefore, just simply being born a woman acts as a significant risk factor. 

When should I see a doctor?

See a doctor1 immediately if:

  • You experience some or all of the signs and symptoms of gigantomastia 
  • Your symptoms worsen 
  • Your symptoms negatively impact your daily life 
  • You have problems breastfeeding, if pregnant 


Defined as massive breast enlargement, gigantomastia, ‘’breast hypertrophy’’, or ‘’macromastia’’ is a rare, physically, psychologically, and socially disabling condition that: a) solely affects females, and b) is often benign (noncancerous), and idiopathic (unknown cause). 

Gigantomastia is characterised by excessive breast growth that causes breast tissue to:

  • Weigh more than 5 pounds
  • Exceed 3% of total body weight 

Unfortunately, gigantomastia cannot be prevented as its exact causes remain a mystery to this day. However, it is believed that gigantomastia is caused by certain factors including:

  • Pregnancy (gestational gigantomastia)
  • Puberty (juvenile gigantomastia)
  • Certain medications (medication-induced gigantomastia): e.g. penicillamine 
  • Certain autoimmune conditions: e.g. lupus 
  • Genetics
  • Extreme obesity

Having extremely large and heavy breasts puts a lot of strain not only on the breasts, but on the shoulders, neck, and back as well. As a result, many women with gigantomastia are left unable to walk, exercise, breastfeed, or even work, further leading to obesity and mental disorders including anxiety and depression. 

Doctors will usually diagnose gigantomastia by checking the patient’s medical history and performing a physical examination. No further diagnostic tests are often needed to confirm the diagnosis. 

Mild to moderate gigantomastia is often managed and treated via medications alone or in combination with breast reduction surgery (also known as ‘’reduction mammaplasty’’).  Severe or recurring gigantomastia, on the other hand, is mainly treated by breast removal surgery (also known as ‘’mastectomy’’). 

See a doctor immediately mainly if:

  • You experience the symptoms of gigantomastia
  • Your symptoms worsen and negatively impact your physical and/or mental health
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Haajar Dafiri

Bachelor of Science with Honours – BSc (Hons), Biochemistry, University of
Wolverhampton, UK

Haajar Dafiri is a recent First Class BSc (Hons) Biochemistry graduate from the University of Wolverhampton with over 4 years of academic writing experience.
She has professional experience working in both labs and hospitals such as LabMedExpert and the NHS, respectively. Due to her ‘’outstanding undergraduate’’ academic achievements, she was awarded both the Biosciences Project Prize and the Biochemical Society Undergraduate Recognition Award.

From a young age, whenever words and science were involved, Haajar eagerly followed. Haajar particularly enjoys diving deep into intricate research articles and interpreting, analysing and communicating the scientificfindings to the general public in an easy, fun and organised manner – hence, why she joined Klarity. She hopes her unique, creative and quirky writing style will ignite the love of science in many whilst putting a smile on their faces.

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