Medical treatment has not proven consistently effective. Medical regimens have included tamoxifen, progesterone, bromocriptine, the gonadotropin-releasing hormone agonist leuprolide, and testosterone. Gestational macromastia has been treated with breast reduction drugs alone without surgery. Surgical therapy includes reduction mammaplasty and mastectomy. However, breast reduction is not clinically indicated unless at least 1.8 kg (4 lb) of tissue per breast needs to be removed. In the majority of cases of macromastia, surgery is medically unnecessary, depending on body height. Topical treatment includes regimens of ice to cool the breasts.

Treatment of hyperprolactinemia-associated macromastia with D receptor agonists such as bromocriptine and cabergoline has been found to be effective in some, but not all cases. Danazol, an antiestrogen and weak androgen, has also been found to be effective in the treatment of macromastia.

When hypertrophy occurs in adolescence, noninvasive treatments, including pharmaceutical treatment, hormone therapy, and steroid use are not usually recommended due to known and unknown side effects. Once a girl's breast growth rate has stabilized, breast reduction may be an appropriate choice. 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.

Pregnancy is recognized as the second most common reason for hypertrophy. When secondary to pregnancy, it may resolve itself without treatment after the pregnancy ends.

The mother must remove the breast milk. If the baby can attach well and suckle, then she should breastfeed as frequently as the baby is willing. If the baby is not able to attach and suckle effectively, she should express her milk by hand or with a pump a few times until the breasts are softer, so that the baby can attach better, and then get them to breastfeed frequently.

She can apply warm compresses to the breast or take a warm shower before expressing, which helps the milk to flow. She can use cold compresses after feeding or expressing, which helps to reduce the oedema.

Engorgement occurs less often in baby-friendly hospitals which practise the Ten Steps and which help mothers to start breastfeeding soon after delivery.

Regular breastfeeding can be continued. The treatment for breast engorgement can be divided into non-medical and medical methods. The non-medical methods include hot/cold packs, Gua-Sha (scraping therapy), acupuncture and cabbage leaves whereas medical methods are proteolytic enzymes such as serrapeptase, protease, and subcutaneous oxytocin. Evidence from published clinical trials on the effectiveness of treatment options is of weak quality and is not strong enough to justify a clinical recommendation.

The development of breast cysts may be prevented to some degree, according to the majority of the specialists. The recommended measures one is able to take in order to avoid the formation of the cysts include practicing good health and avoiding certain medications, eating a balanced diet, taking necessary vitamins and supplements, getting exercise, and avoiding stress.

Although caffeine consumption does not have a scientifically proved connection with the process of cyst development, many women claim that their symptoms are relieved if avoiding it. Some doctors recommend reducing the amount of caffeine in one's diet in terms of both beverages and foods (such as chocolate). Also reducing salt intake may help in alleviating the symptoms of breast cysts, although, again, there is no scientific linkage between these two. Excessive sugar consumption as well as undetected food allergies, such as to gluten or lactose, may also contribute to cyst development.

The appearance of tuberous breasts can potentially be changed through surgical procedures, including the tissue expansion method and breast implants.

The procedure to change the appearance of tuberous breasts can be more complicated than a regular breast augmentation, and some plastic surgeons have specialist training in tuberous breast correction. As tuberous breasts are a congenital deformity, referral for treatment under the National Health Service may be possible in the United Kingdom. A starting point for those seeking such a referral may be a visit to their local General Practitioner. For those seeking non-surgical solutions, counseling may be recommended as a way of coming to terms with body image.

In some cases, the accessory breast may not be visible at the surface. In these cases, it may be possible to distinguish their appearance from normal breast tissue with MRI. In other cases, accessory breasts have been known to lactate, as illustrated in a woodcut showing a child nursing at ectopic breast tissue on the lateral thigh.

There is some evidence that the condition may be more common in Native American populations.

Danazol, an estrogen biosynthesis inhibitor, tamoxifen, an antagonistic modulator of the estrogen receptor, and bromocriptine, a prolactin-lowering D receptor agonist, are the main drugs used in the treatment of mastodynia and are effective.

Other medications and supplements have been found to be of benefit. Spironolactone (Aldactone), low dose oral contraceptives, low-dose estrogen have helped to relieve pain. Topical anti-inflammatory medications can be used for localized pain. For anti hormonal treatment, danazol (Danocrine) can be helpful. Tamoxifen citrate is used in some cases of severe breast pain. Vitamin E is not effective in relieving pain nor is Evening primrose oil. Vitamin B and Vitamin A have not been consistently found to be beneficial. Flaxseed has shown some activity in the treatment of cyclic mastalgia.

Pain may be relieved by the use of nonsteroidal anti-inflammatory drugs or, for more severe localized pain, by local anaesthetic. Pain may be relieved psychologically by reassurance that it does not signal a serious underlying problem, and an active life style can also effect an improvement.

Information regarding how the pain is real but not necessarily caused by disease can help to understand the problem. Learning breast self-examination helps to orient the woman to normal and expected texture and structure of the breast and nipple. Yearly breast exams may be suggested. Counseling can also be to describe changes that vary during the monthly cycle. Women on hormone replacement therapy may benefit from a dose adjustment. Another non-pharmacological measure to help relieve symptoms of pain may be to use good bra support. Breasts change during adolescence and menopause and refitting may be beneficial. Applying heat and/or ice can bring relief. Dietary changes may also help with the pain. Methylxanthines can be eliminated from the diet to see if a sensitivity is present. Some clinicians recommending a reduction in salt, though no evidence supports this practice.

Accessory breasts, also known as polymastia, supernumerary breasts, or mammae erraticae, is the condition of having an additional breast. Extra breasts may appear with or without nipples or areolae. It is a condition and a form of atavism which is most prevalent in male humans, and often goes untreated as it is mostly harmless. In recent years, many affected women have had a plastic surgery operation to remove the additional breasts, for purely aesthetic reasons.

A related condition, in which extra nipples form, is called "supernumerary nipple" or "polythelia".

Two small studies provide some indication that wearing a bra may have an overall negative effect on sagging breasts. In a Japanese study, 11 women were measured wearing a standardised fitted bra for three months. They found that breasts became larger and lower, with the underbust measurement decreasing and the overbust increasing, while the lowest point of the breast moved downwards and outwards. The effect was more pronounced in larger-breasted women. This may be related to the particular bra chosen for the experiment, as there was some improvement after changing to a different model.

The procedure to remedy micromastia is breast enlargement, most commonly augmentation mammoplasty using breast implants. Other techniques available involve using muscle flap-based reconstructive surgery techniques (latissimus dorsi and rectus abdominus muscles), microsurgical reconstruction, or fat grafting.

Another potential treatment is hormonal breast enhancement, such as with estrogens.

In Rinker's study, 55% of respondents reported an adverse change in breast shape after pregnancy. Many women mistakenly attribute the changes and their sagging breasts to breastfeeding, and as a result some are reluctant to nurse their infants. Research shows that breastfeeding is not the factor that many thought it was. Rinker concluded that "Expectant mothers should be reassured that breastfeeding does not appear to have an adverse effect upon breast appearance." Also discounted as causes affecting ptosis are weight gain during pregnancy and lack of participation in regular upper body exercise.

Breast hypertrophy is a rare medical condition of the breast connective tissues in which the breasts become excessively large. The condition is often divided based on the severity into two types, macromastia and gigantomastia. Hypertrophy of the breast tissues may be caused by increased histologic sensitivity to certain hormones such as female sex hormones, prolactin, and growth factors. Breast hypertrophy is a benign "progressive" enlargement, which can occur in both breasts (bilateral) or only in one breast (unilateral). It was first scientifically described in 1648.

Any deformity of the breasts is only apparent during puberty and this may lead to psychosexual problems with girls in very early puberty being affected psychologically due to the unusual shape of the breast. Surgical papers about the techniques useful in correcting tubular breasts note that

even when results are not perfect, the psychological impact of treatment is immense, with notable improvements in self-esteem to the level where the person engages in normal social activities.

Most women with fibrocystic changes and no symptoms do not need treatment, but closer follow-up may be advised.

There is no widely accepted treatment or prevention strategy for fibrocystic condition. When treatment of symptoms is necessary it follows the same strategies as treatment for cyclical breast pain.

It is controversial whether benign breast conditions improve or worsen with oral contraceptives or hormone replacement therapy.

A few small-scale studies have indicated that the fibrocystic condition may be improved by dietary changes (especially by a reduced intake of caffeine and related methylxanthines or by a reduced intake of salt) and by vitamin supplements.

Small, preliminary studies have shown beneficial effects of iodine supplementation (such as reducing the presence of breast cysts, fibrous tissue plaques and breast pain) in women with fibrocystic breast changes, with elemental iodine (I) being more effective than iodide (I). It is noted that iodine supplementation, via an iodine-based modulation of estrogen influence in the breast, also appears to inhibit early cancer progression in small studies done on breast cancer cells in a lab.. Since treatment success in a lab is often not replicated in humans, more human research is necessary to determine if iodine supplementation prevents breast cancer

A U.S. National Institutes of Health fact sheet of 2011 reported on a randomized, double-blind, placebo-controlled clinical trial performed on 111 women affected by fibrosis and having a history of breast pain. In this trial, daily doses of iodine led to decreased in breast pain, tenderness and nodularity. It was emphasized that further research to clarify iodine's role in fibrocystic breast disease is needed and that large doses of iodine should only be used under the guidance of a physician.

It is estimated that 7% of women in the western world develop palpable breast cysts.

There is preliminary evidence that women with breast cysts may be at an increased risk of breast cancer, especially at younger ages.

In males, the occurrence of breast cysts is rare and may (but need not) be an indication of malignancy.

Some women who have pain in one or both breasts may fear breast cancer. However, breast pain is not a common symptom of cancer. The great majority of breast cancer cases do not present with symptoms of pain, though breast pain in older women is more likely to be associated with cancer.

There are usually no adverse side effects to this condition. In almost all cases it subsides after menopause. A possible complication arises through the fact that cancerous tumors may be more difficult to detect in women with fibrocystic changes.

Failure to remove breast milk, especially in the first few days after delivery when the milk comes in and fills the breast, and at the same time blood flow to the breasts increases, causing congestion. The common reasons why milk is not removed adequately are delayed initiation of breastfeeding, infrequent feeds, poor attachment, ineffective suckling., a sudden change in breastfeeding routine, suddenly stopping breastfeeding, or if your baby suddenly starts breastfeeding less than usual.

Micromastia (also called hypomastia, breast aplasia, breast hypoplasia, or mammary hypoplasia) is a medical term describing the postpubertal underdevelopment of a woman's breast tissue. Just as it is impossible to define 'normal' breast size, there is no objective definition of micromastia. Breast development is commonly asymmetric and one or both breasts may be small. This condition may be a congenital defect associated with underlying abnormalities of the pectoral muscle (as in Poland's syndrome), related to trauma (typically surgery or radiotherapy) or it may be a more subjective aesthetic description.

Self perceived micromastia involves a discrepancy between a person's body image, and her internalized images of appropriate or desirable breast size and shape. Societal ideals over breast size vary over time, but there exist many conceived ideas involving breasts and sexual attractiveness and identity across different cultures.

A supernumerary nipple (also known as a third nipple, triple nipple, accessory nipple, polythelia or the related condition: polymastia) is an additional nipple occurring in mammals, including humans. Often mistaken for moles, supernumerary nipples are diagnosed in humans at a rate of approximately 1 in 18 people.

The nipples appear along the two vertical "milk lines," which start in the armpit on each side, run down through the typical nipples and end at the groin. They are classified into eight levels of completeness from a simple patch of hair to a milk-bearing breast in miniature.

"Polythelia" refers to the presence of an additional nipple alone while "polymastia" denotes the much rarer presence of additional mammary glands.

Although usually presenting on the milk line, pseudomamma can appear as far away as the foot.

A possible relationship with mitral valve prolapse has been proposed.

Breast diseases can be classified either with disorders of the integument, or disorders of the reproductive system. A majority of breast diseases are noncancerous.

Paget's disease of the breast is a type of cancer of the breast. Treatment usually involves a lumpectomy or mastectomy to surgically remove the tumour. Chemotherapy and/or radiotherapy may be necessary, but the specific treatment often depends on the characteristics of the underlying breast cancer.

Invasive cancer or extensive ductal carcinoma "in situ" is primarily treated with modified radical mastectomies. The procedure consists in the removal of the breast, the lining over the chest muscles and a part of the lymph nodes from under the arm. In cases of noninvasive cancers, simple mastectomies are performed in which only the breast with the lining over the chest muscles is removed.

Patients suffering from cancer that has not spread beyond the nipple and the surrounding area are often treated with breast-conserving surgery or lumpectomy. They usually undergo radiation therapy after the actual procedure to prevent recurrence. A breast-conserving surgery consists in the removal of the nipple, areola and the part of the breast that is affected by cancer.

In most cases, adjuvant treatment is part of the treatment schema. This type of treatment is normally given to patients with cancer to prevent a potential recurrence of the disease. Whether adjuvant therapy is needed depends upon the type of cancer and whether the cancer cells have spread to the lymph nodes. In Paget's disease, the most common type of adjuvant therapy is radiation following breast-conservative surgery.

Adjuvant therapy may also consist of anticancer drugs or hormone therapies. Hormonal therapy reduces the production of hormones within the body, or prevents the hormones from stimulating the cancer cells to grow, and it is commonly used in cases of invasive cancer by means of drugs such as tamoxifen and anastrozole.

Most patients diagnosed with Paget's disease of the nipple are over age 50, but rare cases have been diagnosed in patients in their 20s. The average age at diagnosis is 62 for women and 69 for men. The disease is rare among both women and men.

Since the 1980s mastitis has often been divided into non-infectious and infectious sub-groups. However, recent research suggests that it may not be feasible to make divisions in this way. It has been shown that types and amounts of potentially pathogenic bacteria in breast milk are not correlated to the severity of symptoms. Moreover, although only 15% of women with mastitis in Kvist et al.'s study were given antibiotics, all recovered and few had recurring symptoms. Many healthy breastfeeding women wishing to donate breast milk have potentially pathogenic bacteria in their milk but have no symptoms of mastitis.

In lactation mastitis, frequent emptying of both breasts by breastfeeding is essential. Also essential is adequate fluid supply for the mother and baby. Use of pumps to empty the breast is now considered somewhat controversial.

For breastfeeding women with light mastitis, massage and application of heat prior to feeding can help as this may aid unblocking the ducts. However, in more severe cases of mastitis heat or massage could make the symptoms worse and cold compresses are better suited to contain the inflammation.

Nonpuerperal mastitis is treated by medication and possibly aspiration or drainage (see in particular treatment of subareolar abscess and treatment of granulomatous mastitis). According to a BMJ best practice report, antibiotics are generally to be used in all nonpuerperal mastitis cases, with replacement of the antibiotics by an antifungal agent such as fluconazole in cases of deep fungal infections, and corticosteroids are to be used in case of granulomatous mastitis (with differential diagnosis to tuberculosis infection of the breast).

Chemotherapeutic options include:

- Cyclophosphamide plus methotrexate plus fluorouracil (CMF).

- Cyclophosphamide plus doxorubicin plus fluorouracil (CAF).

- Trastuzumab (monoclonal antibody therapy).

Hormonal options include:

- Orchiectomy.

- Gonadotropin hormone releasing hormone agonist (GNRH agonist) with or without total androgen blockage (anti-androgen).

- Tamoxifen for estrogen receptor–positive patients.

- Progesterone.

- Aromatase inhibitors.