Why Haven't I Gotten My Period in Months?

Amenorrhea is a medical term that describes the absence of periods when you are not pregnant. This includes primary amenorrhea in which you have no history of menstruation by age 15 and secondary amenorrhea in which you haven't had a period for more than three months (or six months if you have a history of irregular periods).

That are many reasons why you haven't had a period, ranging from medications, low body weight, and genetics to more serious concerns like thyroid disease and polycystic ovary syndrome (PCOS). An evaluation by a gynecologist and/or endocrinologist may be needed to pinpoint the underlying cause.

Primary Amenorrhea

Primary amenorrhea is the absence of periods since you were born. It is diagnosed when a female has had no period by age 15. Primary amenorrhea is also described when a girl's first period (called menarche) or secondary female sexual characteristics (like breasts or pubic hair) have not occurred by age 14.

The causes of primary amenorrhea are largely related to genetics, although the underlying cause in many cases may never be known.

Turner Syndrome

Turner syndrome is a genetic disorder characterized by a missing or partially missing X chromosome. It affects one of every 2,500 female babies, causing medical and developmental issues such as short height, heart defects, learning disability, and infertility.

About 70% to 80% of females with Turner Syndrome experience delays in puberty, while 90% experience amenorrhea. Hormonal therapy is the mainstay of treatment, including growth hormone (GH) during early childhood to achieve a more typical height and estrogen therapy around age 12 to instigate puberty.

MRKH Syndrome

Mayer–Rokitansky–Küster–Hauser (MRKH) syndrome is a condition in which a female is born with normal external genitals but either has an underdeveloped vagina and uterus or no vagina or uterus at all. Amenorrhea is characteristic of this condition.

Around one of every 5,000 female births results in MRKH syndrome. The cause is thought to be genetic, though no gene has yet been linked to the disorder. Around 15% of cases of primary amenorrhea are due to MRKH syndrome.

Surgery and other specialist procedures may be used in females with MRKH syndrome to create a functional vagina to enable sexual intercourse. Uterine transplants have been performed in a number of people, but it is highly experimental.

Intersex Syndromes

Intersex describes people who have genitals, reproductive organs, or sex characteristics that do not confer to the male/female binary.

Intersex individuals who have female reproductive organs may or may not experience amenorrhea. Those who do are typically diagnosed with conditions like:

• Complete androgen insensitivity syndrome (CAIS), a condition in which the body does not respond appropriately to the male sex hormone testosterone
• 5-alpha-reductase 2 deficiency, a condition in which a person born with female external genitalia or ambiguous genitalia develops male secondary sex characteristics during puberty, including male genitalia
• XY gonadal dysgenesis, a condition in which a person has XY (male) chromosomes and functional female genitals

The treatment varies based on how these disorders affect the reproductive tract, development, or fertility.

Constitutional Delay of Puberty

Constitutional delay of puberty, or simply delayed puberty, is ascribed to any condition in which a girl does not have her first period or develop secondary sexual characteristics by the expected age. It is diagnosed after all other causes of primary amenorrhea have been excluded.

The cause of delayed puberty may be genetic as it tends to run in families. Even so, many cases are idiopathic (of unknown origin). The treatment can vary, with some girls requiring no treatment and others being given hormones to stimulate puberty.

Girls who are chronically underweight may also experience delayed puberty. Dietary and medical interventions, including therapy, may be needed to increase weight and help kickstart puberty.

Secondary Amenorrhea

Secondary amenorrhea occurs when you have normal periods but suddenly stop having them. It refers to the prolonged cessation of menstruation outside of pregnancy or menopause.

By definition, secondary amenorrhea is diagnosed if you have normal periods but then suddenly stop for three months or more. If you have irregular periods (called oligomenorrhea), it is diagnosed when you stop having periods for six months or longer.

Pregnancy should be ruled out before proceeding with looking for further causes of secondary amenorrhea. Aside from pregnancy, it is largely related to conditions that disrupt the normal balance of hormones that regulate your menstrual cycle.

Functional Causes

Women who exercise strenuously and/or lose a lot of body fat can experience changes in hormone production, leading to amenorrhea. This is largely due to a part of the brain called the hypothalamus that synchronizes your periods.

When you are too thin or lack nutrition, the hypothalamus secretes less of a hormone, called gonadotropin-releasing hormone (GnRH), which plays a central role in your cycle. This leads to what is called functional hypothalamic amenorrhea, the most common cause of secondary amenorrhea.

Common causes of hypothalamic amenorrhea include:

• Low body weight disorders like anorexia nervosa
• Excessive exercise
• Inadequate caloric intake
• Chronic emotional stress (which also disrupts hypothalamic function)

Lifestyle adjustments or stress reduction techniques may be all that is needed to set your periods right. Anorexia nervosa is treated with therapy and medications.

Thyroid Disease

Both hyperthyroidism (overactive thyroid) and hypothyroidism (underactive thyroid) can lead to the cessation of periods.

Treating hyperthyroidism with thyroid-suppressing treatments and hypothyroidism with thyroid hormones can help remedy amenorrhea.

Hypothalamus, Pituitary, and Ovary Problems

The hypothalamus-pituitary-ovarian (HPO) axis is a feedback system in which chemical messages are sent back and forth to the hypothalamus, pituitary gland, and ovaries to maintain normal menstrual cycles.

Disruption of the HPO axis can lead to amenorrhea if hormones involved in the menstrual cycle, such as GnRH and prolactin, are increased or decreased. Any disease affecting the hypothalamus, pituitary gland, or ovaries can cause this, including:

• Pituitary adenomas (benign pituitary tumors)
• Prolactinomas (prolactin-secreting pituitary tumors)
• Polycystic ovary syndrome (PCOS)
• Primary ovarian insufficiency (a rare condition causing the ovaries to stop working)
• Kallman syndrome (a congenital condition affecting GnRH levels)

Severe systemic or inflammatory diseases, such as cancer, inflammatory bowel disease (IBD), and lupus, can indirectly interrupt signaling in the HPO axis and also cause amenorrhea.

Medications

Amenorrhea can sometimes be drug-induced. Estrogen therapies are among the most common causes. There are also non-hormonal drugs that can cause suppression of the HPO axis or indirectly affect hormone production.

Some of the more common causes of drug-induced amenorrhea include:

• Hormonal contraceptives used for birth control but also for heavy menstrual bleeding, PCOS, endometriosis, and severe acne
• Antipsychotics, particularly typical antipsychotics and Risperdal (risperidone)
• Chemotherapy
• Antiepileptic drugs like phenobarbital, phenytoin, and carbamazepine
• Heroin

Most cases of drug-induced amenorrhea are reversible once treatment is stopped or changed.

When to Call a Healthcare Provider

Generally speaking, a female who has not had her first period by age 15 or has no secondary sexual characteristics by age 14 should be seen by a gynecologist. The American Congress of Obstetricians and Gynecologists (ACOG) recommends girls have their first gynecologic visit between ages 13 and 15.

If you have had normal periods, you should see a gynecologist if you miss three cycles (or six if you have a history of irregular periods). Also see a healthcare provider for any of these symptoms, even with normal periods:

• Abnormal facial or body hair growth
• Sudden loss of scalp hair
• Sudden, unexplained outbreak of acne
• Patches of dark, velvety skin (called acanthosis nigricans)
• An enlarged thyroid gland (goiter)
• Abnormal production of breast milk (lactation)

Diagnosis

Your healthcare provider may recommend performing a pelvic exam to check for any concerns. If you haven't started your period yet, your provider may also examine your breasts and genitals to look for the typical changes that occur during puberty.

Throughout the process, you should be given the opportunity to ask questions and let your provider know if you're feeling uncomfortable at any time. Your comfort and consent are important, and you are in control of the exam.

Because there are so many possible causes for missed periods, more than one test may be needed. Some of the tests your healthcare provider will most likely suggest include:

• Pregnancy test
• Thyroid function test
• Prolactin test

Other tests may be considered depending on the presentation:

• Ovary function test
• Testosterone test
• Ultrasound or other imaging

If other tests show no specific cause, your healthcare provider may want to do a hysteroscopy. During this exam, a thin, lighted camera passes through the vagina and cervix to look at the inside of your uterus.

Summary

There are many reasons why you may have no periods (amenorrhea). In women and girls who have never had a period (referred to as primary amenorrhea), it may be due to genetic disorders like Turner syndrome or delayed puberty.

If you have periods and suddenly stop (called secondary amenorrhea), the most common cause is pregnancy, which should be ruled out before proceeding with further testing. Other causes include excessive exercise, low body weight, chronic stress, thyroid disease, pituitary adenomas, PCOS, primary ovary insufficiency, and drugs like hormonal contraceptives and antipsychotics.

A Word From Verywell

There are many benign reasons for not having a period for months. However, there are also a few serious causes of amenorrhea. If you've gone two to three months or more without your period, you should be evaluated to rule out any concerning issues.

— CORDELIA NWANKWO, MD, MEDICAL EXPERT BOARD