Amenorrhea: causes of missed periods

Missing periods for several months in a row is a reason not for panic, but for a calm review of the causes. Below — about the forms of amenorrhea, about why menstruation may stop, and about how the examination is conducted.

What amenorrhea is

Amenorrhea is the absence of menstruation. Secondary amenorrhea is said to occur when a woman with a previously normal cycle has no periods for 6 months or more, or for 3 months if she previously had oligomenorrhea — infrequent menstruation. The absence of periods in a girl under 16 years of age is called primary amenorrhea.

Amenorrhea is not a diagnosis but a symptom indicating anatomical, biochemical, genetic, physiological or mental disorders. The frequency of secondary amenorrhea is at least 3%. Some cases are physiological: menarche, pregnancy, lactation, menopause.

Primary amenorrhea: causes

Primary amenorrhea is the absence of menstruation and other signs of puberty before 14 years of age, or the absence of periods before 16 years of age when other signs of maturation are present. The doctor assesses the development of secondary sexual characteristics and the condition of the hymen.

Among the causes are gonadal damage (Turner syndrome, anomalies of the development of the uterus and ovaries), extragonadal pathology (hypopituitarism, hypogonadotropic hypogonadism, delayed menarche, congenital adrenal hyperplasia), impaired patency of the vaginal introitus, vagina, cervical canal and uterine cavity. False amenorrhea is distinguished separately: cyclic changes occur, but blood is not released outward.

Menstruation usually begins at about 12 years of age, and a delay in its onset is more often not a cause for concern: in most girls a regular cycle is established by 16–18 years of age.

Secondary amenorrhea: why periods stop

The most common cause is pregnancy. Natural causes also include lactation and menopause. Periods may be absent while on hormonal contraceptives or hormone injections, and after discontinuation the cycle sometimes does not return for longer than 6 months.

Other causes: excess body weight, prolonged intense exercise, body fat content less than 15–17%, severe anxiety or emotional shock, rapid weight loss. Medications for the treatment of cancer and psychoses, increased thyroid function, pituitary tumors, polycystic ovary disease, premature ovarian insufficiency, adrenal disorders, and adhesions in the uterus after curettage (Asherman syndrome) are also mentioned.

In addition to the absence of periods, there may be changes in breast size, weight fluctuations, nipple discharge, acne and male-pattern hair growth, vaginal dryness. With a pituitary tumor, visual impairment and headache are possible.

No periods in an adolescent: when it is concerning

In the first two years after menarche, pauses of 2–12 months are normal. You should consult a doctor if by 14 years of age there are neither periods nor signs of maturation; by 16 years of age there are no periods although other signs are present; or 3 menstruations in a row have been missed with a negative pregnancy test.

Periods during breastfeeding

Lactation is a natural cause of the absence of periods along with pregnancy and menopause; this is a normal variant, not a malfunction.

How examinations are done and when to see a doctor

The doctor takes a history, performs a general and gynecological examination and orders a pregnancy test. Further, blood tests for estradiol, follicle-stimulating and luteinizing hormones, prolactin, testosterone, thyroid-stimulating hormone are possible. Among instrumental methods, pelvic ultrasound, hysterosonography, CT or MRI of the head are used.

It makes sense to book an appointment if:

• three menstruations in a row have been missed, and the pregnancy test is negative;
• there have been no periods for 6 months or more;
• by 14 years of age there are no signs of puberty, by 16 years of age there are no periods;
• headache, visual impairment, nipple discharge or male-pattern hair growth have appeared.

The absence of periods by itself is not a reason to call an ambulance; 103/112 — for life-threatening conditions (for example, stroke or heart attack) and other emergency situations.

The material is for reference: it helps to get oriented, but does not replace a doctor's consultation — conclusions are made by a specialist after examination and tests.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer