Amenorrhea
Absence of menstrual periods, which can be primary or secondary
Quick Facts
- Type: Menstrual / reproductive condition
- Primary: Periods never started by the expected age
- Secondary: Periods stop after previously occurring
- First step: Rule out pregnancy
Overview
Amenorrhea is the medical term for the absence of menstrual periods. It is described in two main forms. Primary amenorrhea means periods have not started by the expected age in adolescence. Secondary amenorrhea means periods stop for several months or more in someone who previously had regular cycles.
Missing periods is a symptom rather than a disease in itself, and the most common cause in someone of reproductive age is pregnancy. Other causes range from natural events like breastfeeding and menopause to hormone imbalances, stress, low body weight, and certain medical conditions. Identifying the cause guides whether treatment is needed.
Symptoms
The main feature is the absence of periods. Depending on the underlying cause, other symptoms may accompany it, such as:
- Milky nipple discharge
- Hair loss or, conversely, excess facial and body hair
- Headache or vision changes
- Acne and a deeper voice in some hormone conditions
- Hot flashes, vaginal dryness, or night sweats (if related to low estrogen)
- Pelvic pain or, in primary amenorrhea, a lack of other signs of puberty
These associated symptoms can offer clues to the cause and are worth reporting to a clinician.
Causes
Amenorrhea has many possible causes:
- Natural causes: Pregnancy, breastfeeding, and menopause.
- Hormonal conditions: Polycystic ovary syndrome (PCOS), thyroid disorders, and high levels of the hormone prolactin.
- Lifestyle factors: Significant stress, very low body weight, eating disorders, or intense exercise.
- Structural causes: Problems with the reproductive organs, present from birth or acquired.
- Premature ovarian failure, when the ovaries stop working before age 40.
- Medications and contraceptives, some of which reduce or stop periods.
Risk Factors
- Very low body weight or an eating disorder
- Intense athletic training
- High or chronic stress
- Polycystic ovary syndrome or thyroid disease
- A family history of early menopause or menstrual problems
- Certain medications and recent stopping of hormonal contraception
Diagnosis
Evaluation starts with a history, examination, and ruling out pregnancy. Tests may include:
- Pregnancy test, the essential first step in someone of reproductive age.
- Blood hormone tests for thyroid hormone, prolactin, and reproductive hormones.
- Pelvic ultrasound to look at the uterus and ovaries.
- Other imaging, such as an MRI of the pituitary gland, if a hormone-producing problem is suspected.
- Additional tests for conditions such as PCOS or, in primary amenorrhea, genetic and structural evaluation.
Treatment
Treatment depends entirely on the cause. Options may include:
- Lifestyle changes: Restoring a healthy weight, reducing excessive exercise, and managing stress can bring back periods when these are the cause.
- Hormone therapy: Hormonal contraceptives or other hormone treatments to regulate cycles or address estrogen deficiency.
- Treating underlying conditions: Such as thyroid disease, high prolactin, or PCOS.
- Medication for specific causes, for example medicines that lower prolactin.
- Surgery in the uncommon cases of a structural problem.
When periods are absent due to natural causes such as breastfeeding or menopause, no treatment is needed unless symptoms require it.
Prevention
- Maintain a balanced diet and healthy body weight
- Avoid excessive exercise without adequate nutrition
- Manage stress and prioritize sleep
- Seek help early for disordered eating
- Keep up with check-ups if you have a hormone or thyroid condition
When to See a Doctor
See a doctor if you have:
- Missed three or more periods in a row, or your periods stop and you are not pregnant
- Not started periods by age 15, or by about 3 years after breast development began
- Absent periods along with milky nipple discharge, excess hair growth, headaches, or vision changes
While amenorrhea itself is rarely an emergency, finding the cause matters for fertility and long-term health, including bone strength when estrogen is low.
Frequently Asked Questions
What is the most common cause of missed periods?
In someone of reproductive age, pregnancy is the most common cause, so a pregnancy test is the first step. Other common causes include stress, significant weight change, intense exercise, hormonal conditions like PCOS or thyroid disease, breastfeeding, and menopause.
What is the difference between primary and secondary amenorrhea?
Primary amenorrhea means menstrual periods have never started by the expected age in adolescence. Secondary amenorrhea means periods that were previously present stop for several months or more. They tend to have different causes and evaluations.
Can stress or exercise stop my periods?
Yes. High stress, very low body weight, and intense exercise without enough nutrition can disrupt the hormones that drive the menstrual cycle and cause periods to stop. Addressing these factors often restores cycles.
Is amenorrhea dangerous?
The missed periods themselves are usually not an emergency, but the underlying cause matters. Long-term low estrogen can weaken bones, and some causes affect fertility, so it is worth getting persistent absent periods evaluated.
When should I see a doctor about missed periods?
See a doctor if you miss three or more periods in a row and are not pregnant, if you have not started periods by age 15, or if absent periods come with nipple discharge, excess hair growth, headaches, or vision changes.
References
- Mayo Clinic. Amenorrhea.
- American College of Obstetricians and Gynecologists (ACOG).
- MedlinePlus, U.S. National Library of Medicine. Absent menstrual periods.
- Office on Women's Health, U.S. Department of Health and Human Services.