Breast pain

INTRODUCTION — Breast pain (mastalgia) is common in women and occasionally occurs in men. Although it is usually mild and self-limited, approximately 15 percent of affected women require treatment [1]. Evaluation of breast pain is important to determine whether the pain is due to normal physiological changes related to hormonal fluctuation or to a pathologic process such as breast cancer. Unfortunately, studies specific to breast pain are limited and often small in number, not well designed, and with limited follow-up.

Breast pain is a rare symptom of breast cancer. Women who present with breast pain but who have a normal examination and imaging studies can be reasonably assured that their risk of breast cancer is similar to that of a woman without breast pain. Most patients do not seek further medical attention for the pain once they are assured that they do not have breast cancer.

While cyclical breast pain has traditionally been attributed to fibrocystic changes, chronic cystic mastitis, and mammary dysplasia [2-4], breast pain and nodularity are so common that the term fibrocystic "disease" has become obsolete, and we suggest that it no longer be used, although it is commonly used by the patient at presentation.

This topic will discuss the etiology, evaluation, and treatment of breast pain in women (algorithm 1). Evaluation of a breast mass or cancer is discussed separately. (See "Clinical manifestations, differential diagnosis, and clinical evaluation of a palpable breast mass" and "Diagnostic evaluation of suspected breast cancer".)

Breast pain caused by inflammatory or infectious etiologies (ie, mastitis) is discussed in other topics. (See "Lactational mastitis" and "Nonlactational mastitis in adults" and "Primary breast abscess" and "Breast cellulitis and other skin disorders of the breast".)

In addition, pain that develops after breast surgery is of a different etiology and is discussed separately. (See "Clinical manifestations and diagnosis of postmastectomy pain syndrome" and "Postmastectomy pain syndrome: Risk reduction and management".)

EPIDEMIOLOGY — Breast pain is common; up to 70 percent of women in Western societies will experience it sometime during their lives [5]. One study of almost 1700 women (mean age 34 years) surveyed by online questionnaire found that over one-half (51.5 percent) had experienced breast pain [6]. Pain was more commonly reported among older women, those with larger breast sizes, and those less fit and/or physically active. In addition, of those who reported symptoms, 41 and 35 percent reported negative impacts from breast pain on their sexual health and sleep, respectively. Ten percent of those symptomatic had reported breast pain as an issue for over half of their lives.

Although not as well studied and characterized, the prevalence of breast pain appears to depend on the population studied. As an example, breast pain is less common in Asian societies, affecting as few as 5 percent of women [7].

CLASSIFICATION AND ETIOLOGY — Breast pain can be classified into three categories: cyclical, noncyclical, and extramammary [8]. Clinically it is more important to differentiate between extramammary and true breast pain than between cyclical and noncyclical pain [9]. This is because the management of cyclical and noncyclical breast pain is similar, while extramammary pain may require a different treatment (algorithm 1). (See 'Extramammary pain' below.)

Cyclical breast pain — Cyclical pain affects two-thirds of patients with true mastalgia. Cyclical pain is associated with hormonal fluctuations of the menstrual cycle, usually presenting in the week prior to onset of menses. It is frequently bilateral and most severe in the upper outer quadrant of the breasts.

Minor cyclical breast discomfort is normal; it begins during the late luteal phase and dissipates with the onset of menses. This is usually bilateral and diffuse pain, sometimes radiating toward the upper outer quadrant. Cyclical breast discomfort is caused by normal hormonal changes associated with ovulation that stimulate the proliferation of normal glandular breast tissue and result in pain. The stimulation of ductal elements by estrogen, stimulation of the stroma by progesterone, and/or stimulation of ductal secretion by prolactin all contribute to cyclical pain during the menstrual cycle. Cyclical breast pain can also be associated with pharmacologic hormonal agents (eg, postmenopausal hormone therapy or oral contraceptive pills).

Noncyclical breast pain — Noncyclical pain affects up to one-third of women with true mastalgia. The pain does not follow the usual menstrual pattern, may be constant or intermittent, and is more likely to be unilateral and variable in its location in the breast. Noncyclical breast pain is more likely to be related to a breast or chest wall lesion. Possible etiologies include:

●Large pendulous breasts – Large pendulous breasts may cause pain due to stretching of Cooper's ligaments. Neck, back, and shoulder pain and headache may be present, as well as a rash under the pendulous breast in the inframammary fold.

●Diet, lifestyle – The role of diet and lifestyle in causing breast pain is uncertain. Although a high-fat diet [10,11], smoking [12-14], and caffeine intake have been associated with breast pain, it is difficult to conduct randomized trials with appropriate blinding that will negate the placebo effect. Hence, there is currently no high-quality evidence to suggest that a low-fat diet, smoking cessation, or caffeine avoidance reduces breast pain. (See 'Therapies not proven by randomized trial data' below.)

●Hormone replacement therapy – Up to one-third of menopausal women receiving postmenopausal hormone therapy experience some degree of noncyclical breast pain, which may spontaneously resolve over time [15-17]. (See "Menopausal hormone therapy: Benefits and risks".)

●Breast cysts – Solitary cysts, particularly when the presentation is with rapid onset, are frequently painful. (See "Breast cysts: Clinical manifestations, diagnosis, and management".)

●Ductal ectasia – Ductal ectasia is characterized by distention of subareolar ducts due to inflammation unrelated to infection. Ductal ectasia may be associated with fever and acute local pain and tenderness caused by penetration of the duct wall by lipid material, which may resolve to leave a subareolar nodule. In one study, the site and degree of duct dilatation correlated with the intensity of noncyclical breast pain [18].

●Mastitis – Mastitis or breast abscess typically presents as a painful, swollen, and red breast in a febrile woman. Mastitis is more prevalent during lactation but can also occur in nonlactating women (eg, idiopathic granulomatous mastitis [IGM]) and/or smokers. The diagnosis and treatment of mastitis are discussed separately. The rest of this topic assumes that mastitis has been excluded by physical examination. (See "Lactational mastitis" and "Nonlactational mastitis in adults".)

●Inflammatory breast cancer – Women with de novo inflammatory breast cancer (primary disease) may present with pain and a rapidly progressing tender, firm, enlarged breast. The skin over the breast is warm and thickened, with a "peau d'orange" (orange skin) appearance, but there is often no fever or leukocytosis (picture 1 and picture 2). (See "Inflammatory breast cancer: Clinical features and treatment".)

●Hidradenitis suppurativa – Hidradenitis suppurativa, although primarily confined to the axilla, can involve the breast and present as breast nodules, drainage, and pain. (See "Hidradenitis suppurativa: Pathogenesis, clinical features, and diagnosis".)

●Other – Other etiologies of breast pain include pregnancy, thrombophlebitis (Mondor's disease), trauma, macrocysts, prior breast surgery, and a variety of medications (hormones as well as some antidepressants, cardiovascular agents, and antibiotics) [19].

Extramammary pain — Some women who present with breast pain actually have referred pain from sources other than the breasts. The breast is innervated by the anterolateral and anteromedial branches of the intercostal nerves (T3 to T5), and irritation of these nerves anywhere along their course can lead to pain that is felt in the breast or nipple [9]. In some studies done in primary care and certain breast clinic settings, it has been found that women presenting with breast pain more often have extramammary pain rather than true mastalgia [9].

Extramammary pain may be from musculoskeletal sources such as the chest wall, spinal or paraspinal disorders, trauma, or scarring from prior biopsy. It may also be related to medical problems such as biliary, pulmonary, esophageal, or cardiac disease.

●Chest wall pain – Chest wall pain is frequently due to pectoralis major muscle injury, related to repetitive activities such as water skiing, raking, rowing, or shoveling. Chest wall pain that presents as bilateral parasternal discomfort can also arise from costochondritis (typically the second through fifth costochondral junctions) or Tietze syndrome (typically the second and third costochondral junctions). Other etiologies of chest wall pain include slipping and clicking ribs and arthritis. (See "Major causes of musculoskeletal chest pain in adults", section on 'Isolated musculoskeletal chest pain syndromes'.)

●Spinal and paraspinal disorders – Radicular chest wall pain may be due to cervical arthritis. This pain typically occurs in older women in whom vertebral, spinal, and paraspinal problems in the neck and upper thorax accumulate with age. Paraspinal muscle spasm and other impingements on the free course of the sensory nerves from the neck and upper thorax can cause a radiculopathy leading to pain or hyperesthesia. Burning pain, which is typical of nerve root pressure, is a common feature. Imaging studies of the neck may reveal the etiology of the pain. (See "Clinical features and diagnosis of cervical radiculopathy".)

●Trauma – Breast pain can be caused by local trauma, such as seat belt injury, child or pet, or intimate partner violence, to the breasts or anterior chest wall. Pain can also be caused by intercostal neuralgia due to a respiratory infection or underlying pleuritic lesions. Additionally, gallbladder disease or ischemic heart disease may present as intermittent chest pain attributed to the breast.

●Postthoracotomy syndrome is an unusual disorder in which a healing chest wound simulates the effect of a suckling infant. It can be associated with an elevated prolactin concentration, breast pain, and milk production. A similar effect can be seen with other forms of chest wall irritation, including burns and chafing from clothing overlying the nipple [20].

HISTORY — It may be helpful to ask women with cyclical pain to record the occurrence and severity of breast pain in a diary and note potential aggravating and ameliorating factors. Questions the patient should be asked about her pain include:

●Where in the breast or axilla does the pain occur?

●Is the pain bilateral?

●What does the pain feel like?

●How severe is the pain?

●If premenopausal: is it phasic, with peaks at midcycle and premenstrually?

●Is it associated with use of oral contraceptive pills or hormone replacement therapy?

●Did it begin after a recent birth or pregnancy loss or termination?

●Is it related to vigorous or repetitive use of the pectoral muscle group?

●Is there a concurrent neck, back, or shoulder problem?

●Are there systemic or other local symptoms, such as fever or erythema?

●Is there a history of recent trauma to the chest?

●Does the pain affect her ability to perform daily activities?

In addition, a complete medical and surgical history and systematic review of systems should be obtained. Breast cancer risk should be assessed. (See "Screening for breast cancer: Strategies and recommendations", section on 'Breast cancer risk determination'.)

Chest wall pain is often lateral and may be burning or knifelike, and localized or diffuse. (See "Major causes of musculoskeletal chest pain in adults".)

PHYSICAL EXAMINATION

Breast — The breast should be examined for signs of inflammation or infection, which would suggest an etiology of mastitis. Mastitis typically presents as a painful, swollen, and red breast in a febrile woman. Mastitis is more prevalent during lactation but can also occur in nonlactating women. The diagnosis and treatment of mastitis is discussed separately. The rest of this topic assumes that mastitis has been excluded by physical examination. (See "Lactational mastitis", section on 'Clinical manifestations' and "Nonlactational mastitis in adults", section on 'Clinical manifestations'.)

The key point in examining a woman with breast pain is to look for signs suggestive of breast malignancy, such as a mass, skin changes, or bloody nipple discharge. (See "Clinical manifestations, differential diagnosis, and clinical evaluation of a palpable breast mass" and "Nipple discharge".)

The four breast quadrants, subareolar areas, axillae, and supraclavicular and infraclavicular areas should be systematically examined with the woman both lying and sitting with her hands on her hips and then above her head. The specific goals of the examination are to:

●Check for skin changes, noting the symmetry and contour of the breasts, position of the nipples, scars, skin retraction, dimpling, edema or erythema, ulceration or crusting of the nipple, and changes in skin color

●Check for enlarged or tender axillary, supraclavicular, or infraclavicular lymph nodes

●Delineate and document breast masses

●Check for nipple discharge

●Identify localized areas of tenderness and relate them to areas of pain noted by the woman and to other physical findings

Women found to have a palpable breast mass, skin changes, or bloody nipple discharge should be referred to a breast specialist for further evaluation and imaging to treat or exclude breast cancer. (See "Diagnostic evaluation of suspected breast cancer".)

Chest wall — Physical examination should also aim at differentiating true breast pain from extramammary pain. Features of breast pain that suggest an extramammary origin include [9]:

●Unilateral, and brought on by activity

●Located very lateral or medial in the breast

●Reproducible by pressure on a specific area of the chest wall

To specifically look for chest wall pain, women may be asked to lie on each side. These positions enable the breast to fall away from the chest wall, which permits palpation of the underlying chest wall muscles and ribs. Women with pain in the lower aspect of their breast should have the breast elevated with one hand and the underlying chest wall palpated with the other [9].

Chest wall pain due to pectoralis major muscle injury can be reproduced by asking the patient to place her hand flat on the iliac wing and push inward.

Women found to have chest wall pain can be reassured that there is no serious underlying cause for the pain, and they can be treated according to the symptoms. (See 'Chest wall pain' below.)

IMAGING — For most women who present with breast pain, a thorough history and physical examination must be performed, and clinical judgment must be used in deciding upon any diagnostic imaging studies (algorithm 1).

Suspicious physical findings present — Women of any age who have suspicious physical findings such as a mass, skin changes, or bloody nipple discharge should undergo mammography with or without ultrasound. These patients should be clinically evaluated to exclude breast cancer, which is beyond the scope of this discussion. (See "Diagnostic evaluation of suspected breast cancer".)

Suspicious physical findings absent — Assuming they are up to date with breast cancer screening (see "Screening for breast cancer: Strategies and recommendations"), women who have breast pain but no other suspicious findings on physical examination may undergo breast imaging selectively based on their presentation and age. Breast imaging, even with a negative result, has been credited with alleviating patient anxiety. Seeking reassurance is often cited as the main reason for imaging in patients with breast pain [21]. Many women do not seek further medical attention after assurance that their pain is not due to breast cancer [22]. However, there is also evidence that imaging does not always provide such assurance [23].

The imaging modalities most commonly used in these clinical scenarios are breast ultrasound and mammography. There are no data to suggest the use of breast magnetic resonance imaging (MRI) for this patient population. (See "Breast imaging for cancer screening: Mammography and ultrasonography".)

●In a case-control study, there was no difference in breast cancer incidence in women undergoing mammography for a painful breast (0.5 percent) compared with the contralateral nonpainful breast (0.5 percent) and compared with women without breast pain (0.7 percent) [21].

●Three studies of ultrasound for focal breast pain without a palpable mass detected cancer in 0 [24], 1.2 [25], and 4.6 percent of patients [26]. In the last study, only one-half of the cancers were detected at the site of the pain.

The American College of Radiology Appropriateness Criteria guidelines recommend the following approach to selecting an imaging modality [27]:

●Women with cyclical or bilateral nonfocal breast pain usually do not require imaging [28,29]; the yield of finding a specific cause with imaging is low. In a retrospective study of over 900 women who underwent breast imaging for isolated breast pain, cancer was detected in only 0.6 percent of average-risk patients, comparable to the expected incidence of 0.5 percent for screening mammography [30].

●Women with noncyclical, unilateral, or focal breast pain that is not extramammary (eg, chest wall pain), as determined by physical examination, should undergo breast imaging to elucidate the underlying etiology and exclude breast cancer. The choice of imaging modality is based on age:

•Women under 30 years of age should undergo ultrasound because it is more accurate than mammography for that age group [31]. Mammography is added if abnormality is found on the ultrasound and/or if a patient's history or risk status justifies the radiation exposure (eg, family history of premenopausal breast cancer). (See "Factors that modify breast cancer risk in women".)

•Women between 30 and 39 years of age should also undergo ultrasound, and unilateral or bilateral mammography should also be performed because in this age group some small cancers are found on mammography but not ultrasound.

•Women age 40 and older should undergo both mammography and ultrasound.

For women who have breast pain but no abnormality on physical examination or imaging studies, the risk for breast cancer is low at approximately 0.5 percent [32,33]. Such patients can be treated supportively, as described in the next sections. Positive findings on imaging studies require appropriate follow-up (eg, biopsy). (See "Breast biopsy".)

TREATMENT — After obtaining normal findings on clinical and imaging studies, reassurance is often all that is required. A simple assurance that the patient does not have breast cancer provides adequate relief for 78 to 85 percent of women [19,22,34]. Such patients would also benefit from a follow-up visit in two to three months to exclude or treat recurrent/persistent pain.

For some women, however, breast pain can cause problems with their activities of daily living. As an example, in a study of 1171 healthy premenopausal women, 11 percent reported moderate-to-severe pain that interfered with sexual activity (48 percent), physical activity (37 percent), social activity (12 percent), and school activity (8 percent) [5,35]. Consequently, these women required treatment for their breast pain.

Approximately 15 percent of women seen in the breast clinic for breast pain require treatment beyond simple reassurance. Breast pain is treated medically (algorithm 1). Breast surgery is not indicated to treat pain in the absence of any breast pathology.

First-line therapy — First-line therapy for breast pain is conservative and typically includes reassurance that this is not a malignancy, physical support, over-the-counter analgesics, and manipulation of hormone-based medications for those who take them. It is typically safe but may not be effective. We prefer to treat with first-line therapy for six months before moving onto one of the second-line therapies, which may be more effective but also have more side effects. Some practitioners also endorse therapies such as caffeine abstinence, smoking cessation, or evening primrose oil (EPO). Although such therapies have not been proven effective by placebo-controlled trials, they are generally harmless and may provide relief for some patients. (See 'Therapies not proven by randomized trial data' below.)

Physical support

●Support garments – A well-fitting brassiere to better support the breast is widely advocated [36]. The use of a support bra with steel underwire tends to reduce mastalgia in women with pendulous breasts. In addition, use of a "sports bra" during exercise has been shown to reduce pain related to breast movement [37,38]. Wearing a soft, supportive bra at night stops the breast pulling down on the chest wall, supports tender breast tissues, and helps many women sleep [9]. Women with asymmetric breasts may benefit from specialized fitting to place extra padding on one side, which permits appropriate support of that side without overcompressing the contralateral side.

●Compresses – Some women obtain relief from application of warm compresses or ice packs or gentle massage. For those who breast feed, ice packs are recommended during the obstructive (prebacterial) phase of puerperal mastitis to decrease milk production regionally and thereby relieve ductal intraluminal pressure and subsequent pain. (See "Common problems of breastfeeding and weaning" and "Lactational mastitis".)

Acetaminophen or NSAID — Acetaminophen or a nonsteroidal anti-inflammatory drug (NSAID), or both, can be used to relieve breast pain [19].

Topical NSAIDs may also be useful. While the weaker types of topical NSAID (eg, ibuprofen gel) may not be effective in relieving breast pain [39], data from randomized trials demonstrated significant improvement in those treated with diclofenac gel with minimal side effects [40].

In the United States (US), two types of topical NSAIDs are available:

●Salicylate, the active ingredient in aspirin, is found in Aspercreme and Nuprin.

●Diclofenac, which has the same active ingredient as the oral NSAID, is available as a patch, gel, or topical solution [41,42].

Second-line therapy — Treatment with one of the second-line therapies may be required in patients who still have breast pain that diminishes quality of life despite first-line therapy for six months. We prefer to use tamoxifen first because it has fewer side effect than danazol [43]. We prefer to treat with tamoxifen or danazol for one to three months, until either pain subsides or side effects increase.

Tamoxifen — For patients with more severe mastalgia refractory to other treatments, tamoxifen can provide breast pain relief. A meta-analysis of three randomized trials found tamoxifen to be more effective in relieving breast pain than placebo (relative risk 1.92, 95% CI 1.42-2.58) [43]. Tamoxifen is effective at both doses of 20 mg daily and 10 mg daily, and the side effects are significantly reduced at the lower dose [44]. Thus, when used off-label to treat severe mastalgia, tamoxifen is usually given at 10 mg once daily for three months.

However, tamoxifen is associated with menopause-like symptoms such as hot flashes, vaginal dryness, joint pain, and leg cramps. It can also increase the risk of blood clots, strokes, uterine cancer, and cataracts. Thus, tamoxifen is infrequently used to treat mastalgia. Restricting tamoxifen to the luteal phase of the menstrual cycle has also been suggested to reduce side effects [9]. (See "Managing the side effects of tamoxifen and aromatase inhibitors".)

Danazol — Danazol is an androgen, and for severe mastalgia, it is usually given at 200 mg once daily. It should be noted that since 2018, the US Food and Drug Administration (FDA) no longer approves the use of danazol for the indication of fibrocystic breast disease.

Danazol is effective in relieving breast pain and tenderness. According to a meta-analysis of four randomized trials against placebo, it resulted in a 20 point mean reduction in pain score on a visual analogue scale (VAS) of 0 to 100 [43,45,46].

However, the use of danazol is limited by its androgenic effects. At the recommended dose of 200 mg daily, significant proportions of patients reported side effects such as weight gain (30 percent), menstrual irregularity (50 percent), deepening of the voice (10 percent), and hot flashes (10 percent) [47]. Restricting the use of danazol to the luteal phase of the menstrual cycle reduces the side effects without compromising its effectiveness [45].

Women on hormone-based medications — Postmenopausal hormone therapy that causes breast pain should be decreased or discontinued if at all possible [48]. However, this should only be done if breast pain is intolerable and after discussing with the patient the risks and benefits or curtailing hormone replacement therapy. (See "Menopausal hormone therapy: Benefits and risks".)

It is not clear whether oral contraceptives cause or relieve cyclical mastalgia [47]. Decreasing the dose of estrogen in an oral contraceptive regimen can be effective in controlling breast pain. In other studies, oral contraceptives can reduce breast pain severity and duration in some women with cyclical symptoms [49,50]. The impact of oral contraceptive pills on breast pain may largely depend on their compositions; alternatively, they may have different effects on different women.

Progestogens also improve breast pain symptoms in some women [51,52]. While oral [53] and topical (applied to the breast) progesterone [54] did not show benefit in randomized trials, a vaginal cream of micronized progesterone (4 g of vaginal cream containing 2.5% natural progesterone used from the 19^th to the 25^th day of the cycle for six cycles) reduced breast pain in 65 percent of women compared with 22 percent of controls in a trial [55].

Therapies not proven by randomized trial data — The role of diet and lifestyle in relieving cyclical breast pain is unclear, with a strong likelihood of a placebo response for many interventions. However, some practitioners feel that some of these treatments (eg, caffeine abstinence and EPO) are worth trying because they are generally harmless and may offer some women pain relief.

●A low-fat (15 percent of calories), high-complex-carbohydrate diet has been effective in some observational studies and small randomized trials [7,19,56]. However, the trials could not be blinded, which may invite a placebo effect. Additionally, such low-fat diets are difficult to maintain beyond a few weeks.

●Elimination of caffeine has not been effective in controlled trials, although anecdotally it seems to be helpful in some women [10-12].

●EPO or its active ingredient gamma linoleic acid (GLA) has been studied in multiple randomized trials of breast pain [57]. Despite early enthusiasm, neither has been shown to be effective beyond the placebo effect [34,43]. One study suggested that iron deficiency and hypothyroidism in those who do not respond to EPO should be treated, as they could negatively impact the efficacy of EPO [58].

●Vitamin E has been shown in multiple randomized trials to be no better than placebo in the treatment of benign breast disease [59,60], although, again, some women report benefit with its utilization.

●Bromocriptine is a dopamine agonist that inhibits prolactin release. Although bromocriptine is effective in relieving pain compared with placebo, it is less effective than danazol, and up to 80 percent of women develop side effects such as headaches and dizziness. Therefore, it is no longer used to treat breast pain [9]. Several other drugs that affect estrogen or prolactin secretion (including bromocriptine and other gonadotropin-releasing hormone [GnRH] agonists) have been studied but are not advocated for use in patients with severe mastalgia, because of unfavorable side effect profiles [61,62].

Investigational therapies — Because of the unfavorable side effect profiles of the medications currently used to treat mastalgia (eg, danazol, tamoxifen), there is great interest in developing natural (herbal) products that could relieve breast pain. However, the benefits of most of these products remain unproven due to a lack of vigorous testing in randomized trials.

●Phytoestrogens, such as genistein, isoflavones, and soy milk, have been investigated as treatments for breast pain. Soy milk has been tested against cow milk in a controlled trial, and although an improvement of symptoms was noted in 56 percent of test subjects versus 10 percent of controls, the trial was criticized for noncompliance due to the unpalatable taste of the soy milk.

●Agnus castus, a fruit extract, has significantly lowered visual analogue pain scores against placebo in controlled trials and is well tolerated [63].

●Matricaria chamomilla (chamomile) extract has also improved cyclical breast pain on a visual analogue scale compared with placebo in a controlled trial [64].

Chest wall pain — For women diagnosed with chest wall pain, local heat and analgesics such as acetaminophen or NSAIDs may relieve pain, but most women do not require therapy beyond reassurance that the source of pain is muscle strain or articular. Patients should reduce or cease activities that brought on or aggravated their pain until the pain improves. (See 'Extramammary pain' above.)

In severe cases in which the pain is localized but not relieved by over-the-counter pain medications, a trigger point injection with a mixture of a local anesthetic and corticosteroid may bring relief for the patient and can be repeated as necessary [9].

PROGNOSIS — In general, mastalgia has a natural history of remission and relapse, evidenced by the fact that improvement is seen in as many as 40 percent of women receiving placebo in randomized trials [47]. The prognosis of women who have breast pain is variable and influenced by the age of onset of pain and whether pain is cyclical or noncyclical [22]. In one series, cyclical breast pain spontaneously resolved within three months of onset in 20 to 30 percent of women, but transient relapses were common [65]. In another series, noncyclical breast pain spontaneously resolved in 50 percent of patients [66]. Relief may be spontaneous or related to a hormonally mediated event, such as pregnancy or menopause [22].

ASSOCIATED CONDITIONS — Breast pain is usually a symptom, not a diagnosis. Although most women who have breast pain will not have any associated conditions, some will, in which case their pain should be treated as a component of the associated condition.

Premenstrual syndrome — Premenstrual syndrome (PMS) is characterized by the presence of both physical and behavioral (including affective) symptoms that occur repetitively in the second half of the menstrual cycle and interfere with some aspects of the woman's life. Breast tenderness is one of the common symptoms of PMS. A meta-analysis of 10 randomized trials of selective serotonin reuptake inhibitors (SSRIs) used in women with premenstrual symptoms showed SSRIs to be more effective than placebo at relieving breast pain [67]. Thus, women who have breast pain or tenderness as a component of PMS may benefit from SSRIs. (See "Treatment of premenstrual syndrome and premenstrual dysphoric disorder", section on 'Selective serotonin reuptake inhibitors'.)

Breast cancer — As stated above, the presence of a breast cancer in a patient who presents with only pain is extremely low, ranging from 0.5 to 3.3 percent [19,21,25,68-70]. Breast pain may occur at the time of presentation of a breast cancer, although the pain is typically associated with adjacent benign, cystic breast tissue rather than the cancer. One caveat in retrospective studies is that recall of breast pain might be increased after the diagnosis of breast cancer. In addition, pain may also occur following the imaging and core biopsy of the cancer rather than being associated with the cancer itself.

Prior breast surgery — Pain that develops after breast surgery is of a different etiology and treated differently from de novo breast pain. It is discussed in other topics. (See "Clinical manifestations and diagnosis of postmastectomy pain syndrome" and "Postmastectomy pain syndrome: Risk reduction and management".)

MALE BREAST PAIN — Breast pain in men is usually due to gynecomastia. The causes and management of gynecomastia are discussed in detail elsewhere. (See "Clinical features, diagnosis, and evaluation of gynecomastia in adults" and "Management of gynecomastia" and "Epidemiology, pathophysiology, and causes of gynecomastia" and "Patient education: Gynecomastia (breast enlargement in males) (Beyond the Basics)".)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Evaluation of breast problems".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topics (see "Patient education: Common breast problems (The Basics)")

●Beyond the Basics topics (see "Patient education: Common breast problems (Beyond the Basics)")

SUMMARY AND RECOMMENDATIONS

●Epidemiology – Breast pain (mastalgia) is common in women but rarely a symptom of breast cancer in the absence of corroborating physical or imaging findings. The risk of having a breast cancer in a patient who presents with only breast pain is extremely low, ranging from 0.5 to 3.3 percent. This risk is no higher than that of a woman without breast pain. (See 'Introduction' above and 'Epidemiology' above and 'Breast cancer' above.)

●Etiologies – Breast pain is classified as cyclical, noncyclical, or extramammary. Clinically it is more important to distinguish extramammary pain from true breast pain, as cyclical and noncyclical breast pain are treated similarly. (See 'Classification and etiology' above.)

●Evaluation – Women who present with breast pain should undergo a thorough history and physical examination before clinical judgment is used to determine whether imaging tests are necessary (algorithm 1). (See 'History' above and 'Physical examination' above.)

Assuming they are up to date with breast cancer screening (see "Screening for breast cancer: Strategies and recommendations"), women who have breast pain but lack suspicious findings on physical examination (eg, mass, skin changes, or bloody nipple discharge) may undergo breast imaging selectively based on their presentation and age (see 'Imaging' above):

•Cyclical or bilateral diffuse breast pain usually does not require imaging.

•Noncyclical, unilateral, or focal breast pain that is not extramammary may benefit from breast imaging to elucidate the underlying etiology and exclude breast cancer. Women under 30 years of age should undergo ultrasound, those between 30 and 39 should undergo ultrasound with or without mammography, and those 40 or over should undergo both ultrasound and mammography.

●Treatment – Assurance that the patient does not have breast cancer provides adequate relief for up to 85 percent of women who present with breast pain; 15 percent require further treatment due to pain interfering with daily living.

Breast pain is treated medically; surgery is not indicated in the absence of breast pathology. (See 'Treatment' above.)

•As first-line treatment for breast pain, we suggest conservative measures including physical support, acetaminophen, and/or nonsteroidal anti-inflammatory drugs (Grade 2C). (See 'First-line therapy' above.)

•For women with mastalgia refractory to six months of conservative treatment, we suggest tamoxifen rather than danazol (Grade 2C). Patients should be informed of the significant side effects expected of both medications and be included in the decision-making process. While both medications have shown efficacy in reducing breast pain, danazol is associated with androgenizing effects. We prefer to administer either medication only during the luteal phase to minimize adverse effects. We typically treat for one to three months with either medication until either pain subsides or side effects increase. (See 'Second-line therapy' above.)

•Postmenopausal hormone therapy should be decreased or discontinued if possible after discussion with the patient. Although it is not clear whether oral contraceptives cause or relieve cyclical mastalgia, decreasing the dose of estrogen in an oral contraceptive regimen can be effective in controlling breast pain. (See 'Women on hormone-based medications' above.)

•Although therapies such as caffeine abstinence and evening primrose oil have not been proven effective by vigorous placebo-controlled trials, some practitioners believe they may be tried because these treatments are generally harmless and may relieve pain in some patients. (See 'Therapies not proven by randomized trial data' above.)

●Prognosis – In general, mastalgia has a natural history of remission and relapse. The prognosis is variable and influenced by the age of onset of pain and whether pain is cyclical or noncyclical. Relief may be spontaneous or related to a hormonally mediated event, such as pregnancy or menopause. (See 'Prognosis' above.)

ACKNOWLEDGMENT — The editorial staff at UpToDate acknowledge Dirk Iglehart, MD, who contributed to an earlier version of this topic review.