Resistant ovary syndrome, previously known as Savage syndrome, is a cause of ovarian failure that can lead to secondary amenorrhea. Resistant ovaries result from a functional disturbance of the gonadotropin receptors in the ovarian follicles. It may be a cause of primary or secondary amenorrhea and is resistant to exogenous gonadotropin stimulation.

Diagnosis of this condition requires that the patient has a normal 46,XX karyotype, normal secondary sexual characteristics, elevated plasma follicle-stimulating hormone and luteinizing hormone – in the menopausal range – and that normal, multiple follicles are seen on ovarian biopsy.

Spontaneous reversal of the receptor resistance may occur.

Hyperandrogenism affects 5-10% of females of reproductive age. Hyperandrogenism can affect both males and females, but is more noticeable in females due to the fact that elevated levels of androgens in females often facilitates virilization. Due to the fact that hyperandrogenism is characterized by the elevation of male sex hormone levels, symptoms of hyperandrogenism in men are often negligible. Hyperandrogenism in females is typically diagnosed in late adolescence with a medical evaluation. The medical evaluation tends to consist of a pelvic exam, observation of external symptoms, and a blood test measuring androgen levels.

OHSS is divided into the categories mild, moderate, severe, and critical.

In mild forms of OHSS the ovaries are enlarged (5–12 cm) and there may be additional accumulation of ascites with mild abdominal distension, abdominal pain, nausea, and diarrhea. In severe forms of OHSS there may be hemoconcentration, thrombosis, distension, oliguria (decreased urine production), pleural effusion, and respiratory distress. Early OHSS develops before pregnancy testing and late OHSS is seen in early pregnancy.

Criteria for severe OHSS include enlarged ovary, ascites, hematocrit > 45%, WBC > 15,000, oliguria, creatinine 1.0-1.5 mg/dl, creatinine clearance > 50 ml/min, liver dysfunction, and anasarca. Critical OHSS includes enlarged ovary, tense ascites with hydrothorax and pericardial effusion, hematocrit > 55%, WBC > 25,000, oligoanuria, creatinine > 1.6 mg/dl, creatinine clearance < 50 ml/min, renal failure, thromboembolic phenomena, and ARDS.

Hyperandrogenism, especially high levels of testosterone, can cause serious adverse effects on women’s bodies if left untreated. High testosterone levels have been seen to be associated with obesity, hypertension, amenorrhea(stop of menstrual cycles), and ovulatory dysfunction, which can lead to infertility. The more prominent signs of hyperandrogenism are hirsutism (unwanted growth of hair especially in the abdominal region and places on the back), acne after adolescence, deepening of voice, and alopecia(balding). Hyperandrogenism has also been seen to cause individuals to have a high tolerance to insulin, which can lead to type two diabetes, and dyslipidemia, such as high cholesterol. These effects have also been seen to have a large psychological impact on the individual, sometimes often leading to societal anxiety and depression, especially in adolescent girls and young women. Paired with obesity and hirsutism, it can cause the individual to have low self-esteem, and a poor view of oneself.

Symptoms are set into 3 categories: mild, moderate, and severe. Mild symptoms include abdominal bloating and feeling of fullness, nausea, diarrhea, and slight weight gain. Moderate symptoms include excessive weight gain (weight gain of greater than 2 pounds per day), increased abdominal girth, vomiting, diarrhea, darker urine, decreased urine output, excessive thirst, and skin and/or hair feeling dry (in addition to mild symptoms). Severe symptoms are fullness/bloating above the waist, shortness of breath, pleural effusion, urination significantly darker or has ceased, calf and chest pains, marked abdominal bloating or distention, and lower abdominal pains (in addition to mild and moderate symptoms).

Hyperthecosis (or ovarian hyperthecosis) is hyperplasia of the theca interna of the ovary. Hyperthecosis occurs when an area of luteinization occurs along with stromal hyperplasia. The luteinized cells produce androgens, which may lead to hirsutism and virilization (or masculinization) in affected women.

The term hyperthecosis refers to the presence of nests of luteinized theca cells in the ovarian stroma due to differentiation of the ovarian interstitial cells into steroidogenically active luteinized stromal cells. These nests or islands of luteinized theca cells are scattered throughout the stroma of the ovary, rather than being confined to areas around cystic follicles as in polycystic ovary syndrome (PCOS). These luteinized theca cells result is greater production of androgens.

Seen as a severe form of PCOS, the clinical features of hyperthecosis are similar to those of PCOS. Women with hyperthecosis often have more markedly elevated testosterone, more hirsutism, and are much more likely to be virilized. While elevated androgens in postmenopausal women is rare, hyperthecosis can present in both premenopausal or postmenopausal women. Women with hyperthecosis may or may not have always had underlying PCOS.

FSH insensitivity presents itself in females as two clusters of symptoms: 1) hypergonadotropic hypogonadism or hypoestrogenism, resulting in a delayed, reduced, or fully absent puberty and associated sexual infantilism (if left untreated), reduced uterine volume, and osteoporosis; and 2) ovarian dysgenesis or failure, resulting in primary or secondary amenorrhea, infertility, and normal sized to slightly enlarged ovaries. Males on the other hand are significantly less affected, presenting merely with partial or complete infertility, reduced testicular volume, and oligozoospermia (reduced spermatogenesis).

Follicle-stimulating hormone (FSH) insensitivity, or ovarian insensitivity to FSH in females, also referable to as ovarian follicle hypoplasia or granulosa cell hypoplasia in females, is a rare autosomal recessive genetic and endocrine syndrome affecting both females and males, with the former presenting with much greater severity of symptomatology. It is characterized by a resistance or complete insensitivity to the effects of follicle-stimulating hormone (FSH), a gonadotropin which is normally responsible for the stimulation of estrogen production by the ovaries in females and maintenance of fertility in both sexes. The condition manifests itself as hypergonadotropic hypogonadism (decreased or lack of production of sex steroids by the gonads despite high circulating levels of gonadotropins), reduced or absent puberty (lack of development of secondary sexual characteristics, resulting in sexual infantilism if left untreated), amenorrhea (lack of menstruation), and infertility in females, whereas males present merely with varying degrees of infertility and associated symptoms (e.g., decreased sperm production).

A related condition is luteinizing hormone (LH) insensitivity (termed Leydig cell hypoplasia when it occurs in males), which presents with similar symptoms to those of FSH insensitivity but with the symptoms in the respective sexes reversed (i.e., hypogonadism and sexual infantilism in males and merely problems with fertility in females); however, males also present with feminized or ambiguous genitalia (also known as pseudohermaphroditism), whereas ambiguous genitalia does not occur in females with FSH insensitivity. Despite their similar causes, LH insensitivity is considerably more common in comparison to FSH insensitivity.

In women, a high blood level of prolactin often causes hypoestrogenism with anovulatory infertility and a decrease in menstruation. In some women, menstruation may disappear altogether (amenorrhoea). In others, menstruation may become irregular or menstrual flow may change. Women who are not pregnant or nursing may begin producing breast milk. Some women may experience a loss of libido (interest in sex) and breast pain, especially when prolactin levels begin to rise for the first time, as the hormone promotes tissue changes in the breast. Intercourse may become difficult or painful because of vaginal dryness.

In men, the most common symptoms of hyperprolactinaemia are decreased libido, sexual dysfunction (in both men and women), erectile dysfunction, infertility, and gynecomastia. Because men have no reliable indicator such as menstruation to signal a problem, many men with hyperprolactinaemia being caused by a pituitary adenoma may delay going to the doctor until they have headaches or eye problems caused by the enlarged pituitary pressing against the adjacent optic chiasm. They may not recognize a gradual loss of sexual function or libido. Only after treatment do some men realize they had a problem with sexual function.

Because of hypoestrogenism and hypoandrogenism, hyperprolactinaemia can lead to osteoporosis.

Gonadotropin insensitivity includes:

- Luteinizing hormone insensitivity

- Follicle-stimulating hormone insensitivity

Symptoms of the condition in males consist of loss of libido, impotence, infertility, shrinkage of the testicles, penis, and prostate, diminished masculinization (e.g., decreased facial and body hair growth), low muscle mass, anxiety, depression, fatigue, vasomotor symptoms (hot flashes), insomnia, headaches, and osteoporosis. In addition, symptoms of hyperestrogenism, such as gynecomastia and feminization, may be concurrently present in males.

In females, hypoandrogenism consist of loss of libido, decreased body hair growth, depression, fatigue, vaginal vasocongestion (which can result in cramps), vasomotor symptoms (e.g., hot flashes and palpitations), insomnia, headaches, osteoporosis and reduced muscle mass. Symptoms of hypoestrogenism may be present in both sexes in cases of severe androgen deficiency (as estrogens are synthesized from androgens).

Anovulation is when the ovaries do not release an oocyte during a menstrual cycle. Therefore, ovulation does not take place. However, a woman who does not ovulate at each menstrual cycle is not necessarily going through menopause. Chronic anovulation is a common cause of infertility.

In addition to the alteration of menstrual periods and infertility, chronic anovulation can cause or exacerbate other long term problems, such as hyperandrogenism or osteopenia. It plays a central role in the multiple imbalances and dysfunctions of polycystic ovary syndrome.

During the first two years after menarche 50% of the menstrual cycles could be anovulatories.

It is in fact possible to restore ovulation using appropriate medication, and ovulation is successfully restored in approximately 90% of cases. The first step is the diagnosis of anovulation. The identification of anovulation is not easy; contrary to what is commonly believed, women undergoing anovulation still have (more or less) regular periods. In general, patients only notice that there is a problem once they have started trying to conceive.

Temperature charting is a useful way of providing early clues about anovulation, and can help gynaecologists in their diagnosis.

Secondary amenorrhea's most common and most easily diagnosable causes are pregnancy, thyroid disease, and hyperprolactinemia. A pregnancy test is a common first step for diagnosis. Hyperprolactinemia, characterized by high levels of the hormone prolactin, is often associated with a pituitary tumor. A dopamine agonist can often help relieve symptoms. The subsiding of the causal syndrome is usually enough to restore menses after a few months. Secondary amenorrhea may also be caused by outflow tract obstruction, often related to Asherman's Syndrome. Polycystic ovary syndrome can cause secondary amenorrhea, although the link between the two is not well understood. Ovarian failure related to early onset menopause can cause secondary amenorrhea, and although the condition can usually be treated, it is not always reversible. Secondary amenorrhea is also caused by stress, extreme weight loss, or excessive exercise. Young athletes are particularly vulnerable, although normal menses usually return with healthy body weight. Causes of secondary amenorrhea can also result in primary amenorrhea, especially if present before onset of menarche.

Primary amenorrhoea can be diagnosed in female children by age 14 if no secondary sex characteristics, such as enlarged breasts and body hair, are present. In the absence of secondary sex characteristics, the most common cause of amenorrhoea is low levels of FSH and LH caused by a delay in puberty. Gonadal dysgenesis, often associated with Turner's Syndrome, or premature ovarian failure may also be to blame. If secondary sex characteristics are present, but menstruation is not, primary amenorrhoea can be diagnosed by age 16. A reason for this occurrence may be that a person phenotypically female but genetically male, a situation known as androgen insensitivity syndrome. If undescended testes are present, they are often removed after puberty (~21 years of age) due to the increased risk of testicular cancer. In the absence of undescended testes, an MRI can be used to determine whether or not a uterus is present. Müllerian agenesis causes around 15% of primary amenorrhoea cases. If a uterus is present, outflow track obstruction may be to blame for primary amenorrhoea.

Anovulation is usually associated with specific symptoms. However, it is important to note that they are not necessarily all displayed simultaneously. Amenorrhea (absence of menstruation) occurs in about 20% of women with ovulatory dysfunction. Infrequent and light menstruation occurs in about 40% of women with ovulatory dysfunction. Another potential symptom is irregular menstruation, where five or more menstrual cycles a year are five or more days shorter or longer than the length of the average cycle. Absence of mastodynia (breast pain or tenderness) occurs in about 20% of women with ovulatory problems. Also possible is increased body mass and facial hair, which is relatively easy to treat, and is often associated with PCOS, or polycystic ovary syndrome.

Examples of symptoms of hypogonadism with underdevelopment of the Gonads (testicles and ovaries) include delayed, reduced, or absent puberty, low libido, and infertility.

Women with a luteoma of pregnancy typically don't show any symptoms. Only 36% of women actually show signs of masculinization. These signs include acne, the growth of dark hair (especially on the face), deepening of the voice, temporal balding, and clitoromegaly. An increase in testosterone levels in the mother doesn't necessarily mean masculinization will occur. During a normal pregnancy, the testosterone level will increase slightly in the first and second trimester, but doubles in the third trimester. The testosterone level also depends on the sex of the fetus; male fetuses cause a bigger increase in testosterone levels than female fetuses.

Hypoandrogenism is caused primarily by either dysfunction, failure, or absence of the gonads ("hypergonadotropic") or impairment of the hypothalamus or pituitary gland ("hypogonadotropic"), which in turn can be caused by a multitude of different stimuli, including genetic conditions (e.g., GnRH/gonadotropin insensitivity and enzymatic defects of steroidogenesis), tumors, trauma, surgery, autoimmunity, radiation, infections, toxins, drugs, and many others. Alternatively, it may be the result of conditions such as androgen insensitivity syndrome or hyperestrogenism. More simply, old age may also be a factor in the development of hypoandrogenism, as androgen levels decline with age.

Ovarian diseases can be classified as endocrine disorders or as a disorders of the reproductive system.

If the egg fails to release from the follicle in the ovary an ovarian cyst may form. Small ovarian cysts are common in healthy women. Some women have more follicles than usual (polycystic ovary syndrome), which inhibits the follicles to grow normally and this will cause cycle irregularities.

Other conditions include:

- Ovarian cancer

- Luteoma

- Hypogonadism

- Hyperthecosis

The classic feature of gynecomastia is male breast enlargement with soft, compressible, and mobile subcutaneous chest tissue palpated under the areola of the nipple in contrast to softer fatty tissue. This enlargement may occur on one side or both. Dimpling of the skin and nipple retraction are not typical features of gynecomastia. Milky discharge from the nipple is also not a typical finding, but may be seen in a gynecomastic individual with a prolactin secreting tumor. An increase in the diameter of the areola and asymmetry of chest tissue are other possible signs of gynecomastia.

Males with gynecomastia may appear anxious or stressed due to concerns about the possibility of having breast cancer.

Signs of hyperestrogenism may include heightened levels of one or more of the estrogen sex hormones (usually estradiol and/or estrone), lowered levels of follicle-stimulating hormone and/or luteinizing hormone (due to suppression of the hypothalamic–pituitary–gonadal axis by estrogen), and lowered levels of androgens such as testosterone (generally only relevant to males). Symptoms of the condition in women may consist of menstrual irregularities, amenorrhea, abnormal vaginal bleeding, and enlargement of the uterus and breasts. It may also present as isosexual precocity in children and as hypogonadism, gynecomastia, feminization, impotence, and loss of libido in males. If left untreated, hyperestrogenism may increase the risk of estrogen-sensitive cancers such as breast cancer later in life.

Examples of symptoms of hypogonadism include delayed, reduced, or absent puberty, low libido, and infertility.

Hyperprolactinaemia or hyperprolactinemia is the presence of abnormally high levels of prolactin in the blood. Normal levels are less than 500 mIU/L [20 ng/mL or µg/L] for women, and less than 450 mIU/L for men.

Prolactin is a peptide hormone produced by the anterior pituitary gland that is primarily associated with lactation and plays a vital role in breast development during pregnancy. Hyperprolactinaemia may cause galactorrhea (production and spontaneous flow of breast milk) and disruptions in the normal menstrual period in women and hypogonadism, infertility and erectile dysfunction in men.

Hyperprolactinaemia can also be a part of normal body changes during pregnancy and breastfeeding. It can also be caused by diseases affecting the hypothalamus and pituitary gland. It can also be caused by disruption of the normal regulation of prolactin levels by drugs, medicinal herbs and heavy metals inside the body. Hyperprolactinaemia may also be the result of disease of other organs such as the liver, kidneys, ovaries and thyroid.

In the majority of young women, hyperandrogenism leads to oily skin, acne, hirutism, menstrual irregularities and, in some cases, androgenic alopecia, clitorimegaly, changes in muscle mass and deepening of the voice. Insulin resistance can be present in different forms; some persons have high concentrations of insulin but normal levels of glucose, while others have glucose measurements in the diabetic range. A history of diabetic symptoms such as polydipsia, polyuria and weight loss may sometimes, but not always, be present. Other related symptoms to HAIR-AN syndrome include enlarged clitoris, increased libido, glucose intolerance, irregular menstruation, increased blood pressure, infertility. Obesity is also one such symptoms in some women, and is also marked in women affected by PCOS, hirsutism, acanthosis nigricans.

Estrogen insensitivity syndrome (EIS), or estrogen resistance, is a form of congenital estrogen deficiency or hypoestrogenism which is caused by a defective estrogen receptor (ER) – specifically, the estrogen receptor alpha (ERα) – that results in an inability of estrogen to mediate its biological effects in the body. Congenital estrogen deficiency can alternatively be caused by a defect in aromatase, the enzyme responsible for the biosynthesis of estrogens, a condition which is referred to as aromatase deficiency and is similar in symptomatology to EIS.

EIS is an extremely rare occurrence. As of 2016, there have been three published reports of EIS, involving a total of five individuals. The reports include a male case published in 1994, a female case published in 2013, and a familial case involving two sisters and a brother which was published in 2016.

EIS is analogous to androgen insensitivity syndrome (AIS), a condition in which the androgen receptor (AR) is defective and insensitive to androgens, such as testosterone and dihydrotestosterone (DHT). The functional opposite of EIS is hyperestrogenism, for instance that seen in aromatase excess syndrome.