[4][5] The enlargement can cause muscular discomfort and over-stretching of the skin envelope, which can lead in some cases to ulceration.

A diagnosis is made when an adolescent's breasts grow rapidly and achieve great weight, usually soon after their first menstrual period.

[citation needed] At the onset of puberty, some females who have experienced little or no breast development can reportedly reach three or more cup sizes within a few days (see below).

When the swelling in the connective tissue occurs after birth, it can negatively impact long term milk supply.

The woman's breasts can generate extraordinary discomfort, turning feverish, red, itchy, and even causing the skin to peel.

[18] Other types and causes of breast hypertrophy include idiopathic, drug-induced (e.g., penicillamine, ciclosporin, bucillamine), autoimmunity-associated, tumors, and syndromes.

[19][20][21] The underlying cause of the rapidly growing breast connective tissue, resulting in gigantic proportions, has not been well elucidated.

[25] Macromastia occurs in approximately half of women with aromatase excess syndrome (a condition of hyperestrogenism).

[28][29] Macromastia has also been associated with hypercalcaemia (which is thought to be due to excessive production of parathyroid hormone-related protein) and, rarely, systemic lupus erythematosus[25] and pseudoangiomatous stromal hyperplasia.

[31][32] A handful of drugs have been associated with gigantomastia, including penicillamine, bucillamine, neothetazone, ciclosporin, indinavir, and prednisolone.

Medical regimens have included tamoxifen,[35] progesterone, bromocriptine, the gonadotropin-releasing hormone agonist leuprorelin, and testosterone.

In some instances after aggressive or surgical treatment, the breast may continue to grow or re-grow, a complete mastectomy may be recommended as a last resort.

In the case of a 12-year-old Japanese girl reported in 1993, her "massively enlarged" breasts caused her "intense psychological problems, incapacitating her in school activities and social relations".

Ill-fitting bras with narrow straps can cause chronic irritation, redness, and indentations in the shoulders.

[50] In July of that year the Plymouth physician William Durston wrote to the Royal Society, reporting the case of a patient named Elizabeth Travers (sometimes spelled Treves).

Durston's account was soon published in the Society's Philosophical Transactions, and includes the following account of the onset of symptoms:Elizabeth Treves, 23. or 24. years of age, fair of complexion, brown-hair’d, of an healthy constitution, low of stature, of honest repute, but of mean and poor parentage, near this Town [Plymouth], was on Friday July 3d, 1669 in good health, and went well to bed, where she took as good rest and sleep, as ever before, but in the morning, when she awaken’d, and attempted to turn herself in her bed, was not able, finding her Breasts so swell’d, that she was affrighted to an astonishment.

[51]Durston later wrote to the Society to report that Travers had died on October 21 of the same year, four months after the onset of enlargement.

[52] Durston did not, as is sometimes stated, carry out breast reduction or mastectomy, instead favouring a range of medicines, the details of which are redacted in the published account in the Philosophical Transactions.

On December 24, 1849, the left breast, measuring 67 cm (26 in) in circumference, and weighing 2.7 kg (6.0 lb), was removed in a procedure lasting three and a half minutes.

In this instance, the swelling abated about 10 days after childbirth, but her bra cup size remained E to a G for the next year.

[54] Another extreme case was observed in 2008 in Maria Vittoria Hospital in Turin, Italy, where the amount removed from both breasts was 17.2 kg (38 lb).

The growth occurred during puberty making it a case of juvenile gigantomastia, but the patient did not seek treatment until the age of 29.

[55] Another extreme case was observed on August 28, 2003, when a 24-year-old woman was admitted to the Clinical Center Skopje in North Macedonia with gigantomastia of pregnancy and the amount later removed from both breasts was 15 kg (33 lb) in total.

[citation needed] In 2007, a Chilean TV station covered the story of 32-year-old Yasna Galleguillos from Antofagasta, who experienced ongoing back pain, making everyday tasks very difficult to perform.

[58] On October 29, 2009, the Philippine television network GMA News and Public Affairs, producers of Wish Ko Lang ("Just My Wish") hosted by Vicky Morales, profiled the story of Pilma Cabrijas, a 30-year-old woman affected by gigantomastia.

Only 152 centimetres (60 in) tall and weighing 43 kilograms (95 lb), her breasts began to develop at age 11 before the onset of menstruation.

The breasts had begun to grow rapidly at puberty and had reached the point of causing physical impairment and respiratory compromise after one year.