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OVERVIEW — Menstrual cycle disorders can cause a female's periods to be absent or infrequent. Although some females do not mind missing their menstrual period, these changes should always be discussed with a health care provider because they can signal underlying medical conditions and potentially have long-term health consequences. A female who misses more than three menstrual periods (either consecutively or over the course of a year) should see a health care provider.
Amenorrhea — Amenorrhea refers to the absence of menstrual periods, and is classified as either:
●Primary (when menstrual periods have not started by age 15 years)
●Secondary (when menstrual periods are absent for more than three to six months in a female who previously had periods)
Oligomenorrhea — Oligomenorrhea is the medical term for infrequent menstrual periods (fewer than six to eight periods per year).
The causes, evaluation, and treatment of amenorrhea and oligomenorrhea are similar and will be discussed together.
CAUSES OF IRREGULAR PERIODS — The brain (including the hypothalamus and pituitary gland), ovaries, and uterus normally follow a sequence of events once per month that helps to prepare the body for pregnancy (figure 1). Two hormones, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), are made by the pituitary gland. Two other hormones, progesterone and estrogen, are made by the ovaries.
Menstrual cycle disorders can result from conditions that affect the hypothalamus, pituitary gland, ovaries, uterus, cervix, or vagina.
Primary amenorrhea — Some of the more common causes of primary amenorrhea include the following:
●Conditions that are present at birth but may not be noticed until puberty. These conditions include genetic or chromosomal abnormalities and abnormalities of the reproductive organs (eg, if the uterus is not present or developed abnormally).
●All of the conditions that lead to secondary amenorrhea can also cause primary amenorrhea.
Secondary amenorrhea — Pregnancy is the most common of secondary amenorrhea. Other common causes include the following:
●Ovarian conditions, such as polycystic ovary syndrome (PCOS) and ovarian insufficiency (early menopause).
●Hypothalamic amenorrhea. This occurs when the hypothalamus slows or stops releasing gonadotropin-releasing hormone (GnRH), a hormone that influences when a female has a menstrual period.
Hypothalamic amenorrhea is associated with low body weight (defined as weighing 10 percent below ideal body weight) (calculator 1 and calculator 2), a low percentage of body fat, eating disorders such as anorexia nervosa or bulimia nervosa, emotional stress, strenuous exercise, and some medical conditions or illnesses. However, in some cases, there is no obvious explanation for hypothalamic amenorrhea.
●Prolactin-secreting pituitary tumors are another common cause of secondary amenorrhea. (See "Patient education: High prolactin levels and prolactinomas (Beyond the Basics)".)
Oligomenorrhea — Many of the conditions that cause primary or secondary amenorrhea can also cause a female to ovulate irregularly (oligomenorrhea). However, most females who develop infrequent periods have PCOS. (See 'Polycystic ovary syndrome' below.)
EVALUATION OF IRREGULAR PERIODS — The evaluation of amenorrhea/oligomenorrhea includes a complete medical history and physical examination.
History — There are often clues about the cause of amenorrhea in a female's personal and family medical history. A female should mention if she had any health problems during infancy or childhood, when her first period started (if there was a first period), and how frequently periods have occurred since. If known, the female should also mention if there is any family history of irregular menstrual periods.
Other important points include the presence of discharge from the breasts, hot flashes, adult acne, facial or chest hair, and headaches or impaired vision. The clinician will also ask about any medications, herbs, and vitamins used; recent stress; recent gynecologic procedures; changes in weight, diet, or exercise patterns; and illnesses.
Physical examination — During the physical examination, the provider will examine the face, neck, breasts, and abdomen. A pelvic examination will also be performed.
Testing — Depending upon the individual, the clinician may order blood tests. Because pregnancy is the most common cause of secondary amenorrhea, a pregnancy test is usually recommended for females whose menstrual periods have stopped. Blood tests to measure hormone levels will also be ordered.
In selected cases, a magnetic resonance imaging (MRI) test may be done to determine if there are hypothalamic or pituitary gland abnormalities in the brain (figure 2). Occasionally, in females with a suspected chromosomal abnormality, a chromosome analysis may be recommended. A pelvic ultrasound may be recommended to identify abnormalities of the uterus, cervix, and vagina.
TREATMENT OF IRREGULAR PERIODS — The goal of treatment is to correct the underlying condition. For a female who is trying to become pregnant, restoring fertility may be another goal. (See "Patient education: Ovulation induction with clomiphene or letrozole (Beyond the Basics)" and "Patient education: Infertility treatment with gonadotropins (Beyond the Basics)".)
Polycystic ovary syndrome — Polycystic ovary syndrome (PCOS) is a chronic condition that causes infrequent periods and an excess of androgens (male hormones). Most health care providers recommend treating PCOS to re-establish normal menstrual cycles and prevent long-term complications. PCOS "cysts" are normal eggs (follicles), and they are not painful. Females with large, painful cysts should see a gynecologist. PCOS is discussed in detail separately. (See "Patient education: Polycystic ovary syndrome (PCOS) (Beyond the Basics)".)
Hypothalamic amenorrhea — Females with hypothalamic amenorrhea are sometimes able to resume normal menstrual periods after making certain lifestyle changes, such as eating a higher-calorie diet, gaining weight, reducing the intensity or frequency of exercise, and reducing emotional stress.
●Low body weight and/or nutritional deficiencies – Females with eating disorders such as anorexia nervosa or bulimia often need specialized care. This usually includes nutrition counseling and work with eating disorder specialists.
●Strenuous exercise – Although exercise offers many health benefits, exercising frequently or excessively can lead to amenorrhea. Studies suggest that amenorrhea develops when a female's caloric intake is less than she burns with exercise and other daily activities. Most females with amenorrhea associated with exercise have also lost weight (resulting in a weight less than 90 percent of the ideal body weight) (calculator 1 and calculator 2).
For females with exercise-associated amenorrhea, treatments include increasing calorie intake and reducing the frequency and/or intensity of exercise. These measures are particularly important if a female is trying to become pregnant. All females with amenorrhea should be sure to consume 1200 to 1500 mg of calcium daily (or take a calcium supplement) and a vitamin D supplement (400 international units, or 10 micrograms, daily). (See "Patient education: Calcium and vitamin D for bone health (Beyond the Basics)".)
Some clinicians recommend estrogen and progestin hormone replacement (or a hormonal contraceptive, such as a birth control pill) for females with hypothalamic amenorrhea. These treatments can reduce the risk of developing osteoporosis later in life. (See "Patient education: Hormonal methods of birth control (Beyond the Basics)" and "Patient education: Osteoporosis prevention and treatment (Beyond the Basics)".)
Ovarian insufficiency — Normally, a female stops ovulating around the age of 50 years when the eggs are gone; this is called menopause. If a female stops ovulating before age 40 years because eggs are lost too early, this is called primary ovarian insufficiency (or premature ovarian failure). (See "Patient education: Primary ovarian insufficiency (Beyond the Basics)".)
Being diagnosed with ovarian insufficiency is usually unexpected. The female should alert the doctor if she is having unusual symptoms, such as hot flashes and night sweats, so that she is tested. Finding out that a person has ovarian insufficiency can be distressing, especially if the female has not completed childbearing. In these situations, counseling with a social worker or psychotherapist may be of benefit. With most types of ovarian insufficiency, pregnancy can be achieved using injectable fertility medications and donor eggs. (See "In vitro fertilization: Overview of clinical issues and questions", section on 'When are donor oocytes used?'.)
Although ovarian insufficiency cannot be cured, hormone therapy (HT) with estrogen and progesterone (or a hormonal contraceptive, such as a birth control pill) can help prevent or treat many of the symptoms and long-term consequences of menopause, such as hot flashes, vaginal dryness, and osteoporosis. HT has risks of its own in older females. However, a young (20- to 50-year-old) female who takes HT does not have the same risks as a ≥50-year-old female who takes HT. Current practice is to provide HT for females with primary ovarian insufficiency until age 50 years, the average age of menopause.
High prolactin — Females with amenorrhea and hyperprolactinemia can usually have normal menstrual periods and become pregnant when treated with medications called dopamine agonists (bromocriptine and cabergoline are examples). This is discussed in detail separately. (See "Patient education: High prolactin levels and prolactinomas (Beyond the Basics)".)
Hypothalamic or pituitary conditions — Some hypothalamic and pituitary gland conditions that cause amenorrhea, such as a congenital deficiency of gonadotropin-releasing hormone (GnRH), are irreversible. (See "Isolated gonadotropin-releasing hormone deficiency (idiopathic hypogonadotropic hypogonadism)".)
However, females with these conditions can have menstrual periods and become pregnant when treated with injectable fertility medications. (See "Patient education: Infertility treatment with gonadotropins (Beyond the Basics)".)
Endometrial adhesions (Asherman syndrome) — Some gynecologic procedures, such as a dilatation and curettage (D and C), can cause adhesions (a type of scar tissue), which damage the uterine lining. If adhesions are extensive, menstrual blood loss will be reduced or absent. A clinician may recommend surgery to remove the scarred tissue, followed by estrogen treatment to stimulate regrowth of the lining. (See "Patient education: Dilation and curettage (D&C) (Beyond the Basics)".)
Anatomic problems — Surgery is often an effective treatment if amenorrhea is caused by a blockage in the reproductive tract. (See "Congenital anomalies of the hymen and vagina".)
WHERE TO GET MORE INFORMATION — Your health care provider is the best source of information for questions and concerns related to your medical problem.
This article will be updated as needed on our website (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for health care professionals, are also available. Some of the most relevant are listed below.
Patient level information — UpToDate offers two types of patient education materials.
The Basics — The Basics patient education pieces 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.
Patient education: Absent or irregular periods (The Basics)
Patient education: Menstruation (The Basics)
Patient education: Infertility in couples (The Basics)
Patient education: Hemochromatosis (The Basics)
Patient education: Pituitary adenoma (The Basics)
Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.
Patient education: High prolactin levels and prolactinomas (Beyond the Basics)
Patient education: Ovulation induction with clomiphene or letrozole (Beyond the Basics)
Patient education: Infertility treatment with gonadotropins (Beyond the Basics)
Patient education: Primary ovarian insufficiency (Beyond the Basics)
Patient education: Polycystic ovary syndrome (PCOS) (Beyond the Basics)
Patient education: Calcium and vitamin D for bone health (Beyond the Basics)
Patient education: Hormonal methods of birth control (Beyond the Basics)
Patient education: Osteoporosis prevention and treatment (Beyond the Basics)
Patient education: Dilation and curettage (D&C) (Beyond the Basics)
Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.
Functional hypothalamic amenorrhea: Pathophysiology and clinical manifestations
Definition, clinical features, and differential diagnosis of polycystic ovary syndrome in adolescents
Evaluation and management of primary amenorrhea
Evaluation and management of secondary amenorrhea
Congenital anomalies of the hymen and vagina
Isolated gonadotropin-releasing hormone deficiency (idiopathic hypogonadotropic hypogonadism)
In vitro fertilization: Overview of clinical issues and questions
The following organizations also provide reliable health information.
●National Library of Medicine
●Hormone Health Network
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