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.

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.

Breast cancer risk is elevated for defined fraction of lesions. Except for patients with a strong family history of breast cancer, where the risk is two-fold, nonproliferative lesions have no increased risk. Proliferative lesions also have approximately a 2-fold risk. In particular, atypical hyperplasia is associated with an increased risk of developing breast cancer. Atypical lobular hyperplasia is associated with the greatest risk, approximately 5-fold and especially high relative risk of developing premenopausal breast cancer. Atypical ductal hyperplasia is associated with 2.4-fold risk. In contrast, a New England Journal of Medicine article states that for women with a strong familial history of breast cancer, the risk of future breast cancer is roughly doubled, independent of histological status. The article further states "The relative risk of breast cancer for the cohort was 1.56 (95 percent confidence interval, 1.45 to 1.68), and this increased risk persisted for at least 25 years after biopsy. The relative risk associated with atypia was 4.24 (95 percent confidence interval, 3.26 to 5.41), as compared with a relative risk of 1.88 (95 percent confidence interval, 1.66 to 2.12) for proliferative changes without atypia and of 1.27 (95 percent confidence interval, 1.15 to 1.41) for nonproliferative lesions. The strength of the family history of breast cancer, available for 4808 women, was a risk factor that was independent of histologic findings. No increased risk was found among women with no family history and nonproliferative findings. In the first 10 years after the initial biopsy, an excess of cancers occurred in the same breast, especially in women with atypia."

It is not well understood whether the lesions are precursors of breast cancer or only indication of increased risk, for most types of lesions the chance of developing breast cancer is nearly the same in the affected and unaffected breast (side) indicating only coincidence of risk factors. For atypical lobular hyperplasia there is high incidence of ipsilateral breast cancers indicating a possible direct carcinogenetic link.

Two percent of women will have a Bartholin's gland cyst at some point in their lives. They occur at a rate of 0.55 per 1000 person-years and in women aged 35–50 years at a rate of 1.21 per 1000 person-years. The incidence of Bartholin duct cysts increases with age until menopause, and decreases thereafter. Hispanic women may be more often affected than white women and black women. The risk of developing a Bartholin's gland cyst increases with the number of childbirths.

While Bartholin cysts can be quite painful, they are not life-threatening. New cysts cannot absolutely be prevented from forming, but surgical or laser removal of a cyst makes it less likely that a new one will form at the same site. Those with a cyst are more likely than those without a cyst to get one in the future. They can recur every few years or more frequently. Many women who have marsupialization done find that the recurrences may slow, but do not actually stop.

Most women of reproductive age develop small cysts each month, and large cysts that cause problems occur in about 8% of women before menopause. Ovarian cysts are present in about 16% of women after menopause and if present are more likely to be cancer.

Benign ovarian cysts are common in asymptomatic premenarchal girls and found in approximately 68% of ovaries of girls 2–12 years old and in 84% of ovaries of girls 0–2 years old. Most of them are smaller than 9 mm while about 10-20% are larger macrocysts. While the smaller cysts mostly disappear within 6 months the larger ones appear to be more persistent.

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.

Although most cases of ovarian cysts involve monitoring, some cases require surgery. This may involve removing the cyst, or one or both ovaries. Technique is typically laparoscopic, unless the cyst is particularly large, or if pre-operative imaging suggests malignancy or complex anatomy. In certain situations, the cyst is entirely removed, while with cysts with low recurrence risk, younger patients, or which are in anatomically eloquent areas of the pelvis, they can be drained. Features that may indicate the need for surgery include:

- Persistent complex ovarian cysts

- Persistent cysts that are causing symptoms

- Complex ovarian cysts larger than 5 cm

- Simple ovarian cysts larger 10 cm or larger than 5 cm in postmenopausal patients

- Women who are menopausal or perimenopausal

The clinical management of a cyst of Montgomery depends upon the symptoms of the patient.

If there are no signs of infection, a cyst of Montgomery can be observed, because more than 80% resolve spontaneously, over only a few months. However, in some cases, spontaneous resolution may take up two years. In such cases, a repeat ultrasonography may become necessary. If, however, the patient has signs of an infection, for example reddening (erythema), warmth, pain and tenderness, a treatment for mastitis can be initiated, which may include antibiotics and non-steroidal anti-inflammatory drugs (NSAIDs). With treatment, inflammatory changes usually disappear quickly. In rare cases, drainage may become necessary. A surgical treatment of a cyst of Montgomery, i.e. a resection, may become necessary only if a cyst of Montgomery persists, or the diagnosis is questioned clinically.

The prognosis seems to be excellent. In one series, all adolescent patients with a cyst of Montgomery had a favourable outcome.

Smoking tobacco appears to increase the risk of breast cancer, with the greater the amount smoked and the earlier in life that smoking began, the higher the risk. In those who are long-term smokers, the risk is increased 35% to 50%. A lack of physical activity has been linked to about 10% of cases. Sitting regularly for prolonged periods is associated with higher mortality from breast cancer. The risk is not negated by regular exercise, though it is lowered.

There is an association between use of hormonal birth control and the development of premenopausal breast cancer, but whether oral contraceptives use may actually cause premenopausal breast cancer is a matter of debate. If there is indeed a link, the absolute effect is small. Additionally, it is not clear if the association exists with newer hormonal birth controls. In those with mutations in the breast cancer susceptibility genes "BRCA1" or "BRCA2", or who have a family history of breast cancer, use of modern oral contraceptives does not appear to affect the risk of breast cancer.

The association between breast feeding and breast cancer has not been clearly determined; some studies have found support for an association while others have not. In the 1980s, the abortion–breast cancer hypothesis posited that induced abortion increased the risk of developing breast cancer. This hypothesis was the subject of extensive scientific inquiry, which concluded that neither miscarriages nor abortions are associated with a heightened risk for breast cancer.

A number of dietary factors have been linked to the risk for breast cancer. Dietary factors which may increase risk include a high fat diet, high alcohol intake, and obesity-related high cholesterol levels. Dietary iodine deficiency may also play a role. Evidence for fiber is unclear. A 2015 review found that studies trying to link fiber intake with breast cancer produced mixed results. In 2016 a tentative association between low fiber intake during adolescence and breast cancer was observed.

Other risk factors include radiation and shift-work. A number of chemicals have also been linked, including polychlorinated biphenyls, polycyclic aromatic hydrocarbons, and organic solvents Although the radiation from mammography is a low dose, it is estimated that yearly screening from 40 to 80 years of age will cause approximately 225 cases of fatal breast cancer per million women screened.

The fertility drug clomiphene citrate (Clomid, Serophene), used to induce ovulation, increases the risk of a corpus luteum cyst developing after ovulation. These cysts don't prevent or threaten a resulting pregnancy. Women on birth control pills usually do not form these cysts; in fact, preventing these cysts is one way birth control pills work.

In contrast, the progesterone-only pill can cause increased frequency of these cysts.

The periareolar glands of Montgomery in the breast are also called Montgomery tubercles or Morgagni tubercles. These periareolar glands are small, papular tissue projections at the edge of the areola (nipple).

Obstruction of the Montgomery tubercles may result in an acute inflammation, a clear or light brownish fluid may drain out of the areola (nipple discharge), and an subareolar mass may develop, the cyst of Montgomery.

Risk factors can be divided into two categories:

- "modifiable" risk factors (things that people can change themselves, such as consumption of alcoholic beverages), and

- "fixed" risk factors (things that cannot be changed, such as age and biological sex).

The primary risk factors for breast cancer are being female and older age. Other potential risk factors include genetics, lack of childbearing or lack of breastfeeding, higher levels of certain hormones, certain dietary patterns, and obesity. Recent studies have indicated that exposure to light pollution is a risk factor for the development of breast cancer.

Blocked sebaceous glands, swollen hair follicles, high levels of testosterone and the use of androgenic anabolic steroids will cause such cysts.

A case has been reported of a sebaceous cyst being caused by the human botfly.

Hereditary causes of sebaceous cysts include Gardner's syndrome and basal cell nevus syndrome.

A nabothian cyst (or nabothian follicle) is a mucus-filled cyst on the surface of the cervix. They are most often caused when stratified squamous epithelium of the ectocervix (toward the vagina) grows over the simple columnar epithelium of the endocervix (toward the uterus). This tissue growth can block the cervical crypts (subdermal pockets usually 2–10 mm in diameter), trapping cervical mucus inside the crypts.

Theca lutein cyst is a type of bilateral functional ovarian cyst filled with clear, straw-colored fluid. To be classified a functional cyst, the mass must reach a diameter of at least three centimeters.

These cysts result from exaggerated physiological stimulation (hyperreactio luteinalis) and are usually associated with markedly elevated levels of beta-human chorionic gonadotropin (beta-hCG). They are thus associated with gestational trophoblastic disease (molar pregnancy), diabetes mellitus, alloimmunisation to Rh-D, and multiple gestations. They have rarely been associated with chronic kidney disease (secondary to reduced hCG clearance) and hyperthyroidism (given the structural homology with TSH). These cysts resolve after pregnancy. Rarely, when the theca-lutein cysts are stimulated by gonadotropins, massive ascites can result. In most cases however, abdominal symptoms are minimal and restricted to peritoneal irritation from cyst hemorrhage. Surgical intervention may be required to remove ruptured or infarcted tissue.

Women who smoke have a twofold increase for functional cysts.

Nabothian cysts are considered harmless and usually disappear on their own, although some will persist indefinitely. Some women notice they appear and disappear in relation to their menstrual cycle. If a woman is not sure the anomaly she has found on her cervix is a nabothian cyst, a visit to a doctor is recommended to rule out other conditions.

Rarely, nabothian cysts have a correlation with chronic cervicitis, an inflammatory infection of the cervix.

Nabothian cysts are not considered problematic unless they grow very large and present secondary symptoms. A physician may wish to perform a colposcopy or biopsy on a nabothian cyst to check for cancer or other problems. Two methods for removing these cysts include electrocautery and cryofreezing, although new cysts may form after the procedure.

A galactocele (also: "lacteal cyst" or "milk cyst") is a retention cyst containing milk or a milky substance that is usually located in the mammary glands. They occur in women during or shortly after lactation.

They present as a firm mass, often subareolar, and are caused by the obstruction of a lactiferous duct. Clinically, they appear similar to a cyst on examination. The duct becomes more distended over time by epithelial cells and milk. It may rarely be complicated by a secondary infection and result in abscess formation.

Once lactation has ended the cyst should resolve on its own without intervention. A galactocele is not normally infected as the milk within is sterile and has no outlet through which to become contaminated.Treatment is by aspiration of the contents or by excision of the cyst. Antibiotics are given to prevent infection.

Galactocele may be associated with oral contraceptive use.

About 90% of pilar cysts occur on the scalp, with the remaining sometimes occurring on the face, trunk and extremities. Pilar cysts are significantly more common in females, and a tendency to develop these cysts is often inherited in an autosomal dominant pattern. In most cases, multiple pilar cysts appear at once.

Treatment for dermoid cyst is complete surgical removal, preferably in one piece and without any spillage of cyst contents. Marsupialization, a surgical technique often used to treat pilonidal cyst, is inappropriate for dermoid cyst due to the risk of malignancy.

The association of dermoid cysts with pregnancy has been increasingly reported. They usually present the dilemma of weighing the risks of surgery and anesthesia versus the risks of untreated adnexal mass. Most references state that it is more feasible to treat bilateral dermoid cysts of the ovaries discovered during pregnancy if they grow beyond 6 cm in diameter.

Epidermoid cysts commonly result from implantation of epidermis into the dermis, as in trauma or surgery. They can also be caused by a blocked pore adjacent to a body piercing. They are also seen in Gardner's syndrome and Nevoid Basal Cell Carcinoma Syndrome on the head and neck. They can be infected by bacteria and form a pimple-like shape.

One proposed cause of pilonidal cysts is ingrown hair. Excessive sitting is thought to predispose people to the condition, as sitting increases pressure on the coccygeal region. Trauma is not believed to cause a pilonidal cyst; however, such an event may result in inflammation of an existing cyst. However, there are cases where this can occur months after a localized injury to the area. Some researchers have proposed that pilonidal cysts may be the result of a congenital pilonidal dimple. Excessive sweating can also contribute to the cause of a pilonidal cyst. Moisture can fill a stretched hair follicle, which helps create a low-oxygen environment that promotes the growth of anaerobic bacteria, often found in pilonidal cysts. The presence of bacteria and low oxygen levels hamper wound healing and exacerbate a forming pilonidal cyst.

An epidermoid cyst is a benign cyst usually found on the skin. The cyst develops out of ectodermal tissue. Histologically, it is made of a thin layer of squamous epithelium.

Dermoid cysts can appear in young children, often near the lateral aspect of the eyebrow (right part of the right eyebrow or left part of the left eyebrow). Depending on the perceived amount of risk, these are sometimes excised or simply kept under observation.

An inflammatory reaction can occur if a dermoid cyst is disrupted, and the cyst can recur if it is not completely excised. Sometimes complete excision is not practical if the cyst is in a dumbbell configuration, whereby it extends through a suture line in the skull.

If dermoid cysts appear on the medial aspect, the possibility of an encephalocele becomes greater and should be considered among the differential diagnoses.

Dermoid cysts develop during pregnancy. They occur when skin cells and things like hair, sweat glands, oil glands or fatty tissue get trapped in the skin as a baby grows in the womb.Dermoid cysts are present at birth (congenital) and are common. It can be months or years before a dermoid cyst is noticed on a child because the cysts grow slowly.

Dermoid cyst symptoms are minor and the cysts are usually painless. They are not harmful to a child’s health. If they become infected, the infection must be treated and the cyst should be removed. It is easier to remove cysts and prevent scars if the cyst is removed before it gets infected.

This type of functional cyst occurs after an egg has been released from a follicle. The follicle then becomes a secretory gland that is known as the corpus luteum. The ruptured follicle begins producing large quantities of estrogen and progesterone in preparation for conception. If a pregnancy doesn't occur, the corpus luteum usually breaks down and disappears. It may, however, fill with fluid or blood, causing the corpus luteum to expand into a cyst, and stay in the ovary. Usually, this cyst is on only one side, and does not produce any symptoms.

In women of reproductive age cysts with a diameter of less than 5 cm are common, clinically inconsequential, and almost always a physiological condition rather than a cancer or other disease condition. In postmenopausal women the threshold for concern is 1 cm. Although ovarian cancer is cystic, it does not arise from benign corpus luteum cysts. Medical specialty professional organizations recommend no follow-up imaging for cysts which are clinical inconsequential.