What is Secondary Amenorrhea?

‘Secondary amenorrhea’ means absence of periods for more than 6 months in someone who previously had irregular periods. or no period for 3 cycles on the background of prior regular cycles. ‘Oligomenorrhea’ is defined as irregular periods, with intervals between menstrual cycles more that 35 days. ‘Primary Amenorrhoea’ is the failure to commence menstruation by the age or 15 years, or 13 years if there are no other signs of puberty commencing and require prompt investigation and referral. This topic is covering secondary amenorrhea which is not a diagnosis in itself, but the trigger for a thorough assessment and timely care.

Why it matters

Periods are controlled by a complex system involving areas in the brain called the hypothalamus and pituitary gland, as well as the ovaries, uterus / endometrial lining, and outflow tract through the cervix and vagina in certain conditions.
When periods stop, it can be temporary, but sometimes it signals an underlying hormonal, metabolic, or structural problem that needs treatment to prevent complications and look after your overall health.

Common Causes of Secondary Amenorrhea

• Ovaries: ~ 40%
  • PMOS (Polyendocrine Metabolic Ovary Syndrome previously known as PCOS): ~ 30%
  • Primary Ovarian Insufficiency (POI): ~ 10%
• Hypothalamus (ie. stress, under-eating, excessive exercise): ~ 35%
• Pituitary (ie. hyperprolactinemia, Sheehan’s Syndrome, Cushing Syndrome): ~ 17%
• Uterus (ie. Asherman’s Sydrome with scar tissue): ~ 7%
• Other causes (ie. thyroid disease, tumours, congenital adrenal hyperplasia ): ~ 1%

🌟 Initial Evaluation

🚫 Exclude pregnancy

Rule out pregnancy first, as this is the most common cause of secondary amenorrhea, and must always be ruled out as the initial step

📝 Detailed History

Key history points include:

• Functional triggers (hypothalamic causes): stress; weight change; restrictive diet / eating disorder symptoms; exercise increase (especially athletes); severe systemic illness
• Medication history. Some drugs can directly cause or contribute to amenorrhea, including: newly started or stopped hormonal contraceptives; androgenic drugs; drugs that increase prolactin
• Hyperandrogenism symptoms (PMOS pattern), including: hirsutism; acne; scalp hair thinning
• Hypothalamic–pituitary red flags, such as: headaches; visual symptoms; fatigue; increased thirst (‘polydipsia’) / urination (‘polyuria’)
• Signs of estrogen deficiency (POI pattern), such as: hot flashes; vaginal dryness; low libido
• Risk factors for uterine scarring (aka. Asherman’s Syndrome), including: D&C; severe obstetric bleeding; endometritis; uterine instrumentation
• Galactorrhea (milk discharge from breasts, suggests hyperprolactinemia)

👩‍⚕️ Physical Examination

Physical examination in this context may include:

• Height, weight, BMI with high BMI more common in PMOS, and low BMI more suggestive of functional hypothalamic causes
• Skin / musculoskeletal markers, such as hirsutism, acne, striae, acanthosis nigricans (insulin resistance)
• Breast exam for galactorrhea
• Vulvovaginal exam for anatomical cause

🧪 Tests

After pregnancy is excluded, the typical starting tests include:

• FSH: high FSH suggests POI. Low FSH with normal E2 suggestive of hypogonadoropric hypogonadism
• Prolactin. Consider hyperprolactinemia and ix further with Pituitary MRI if a true result
• Estradiol (E2)
• TSH
• Total Testosterone, 17-Hydroxyprogesterone, SHBG, DHEAS, Free Androgen Index, LH, HbA1c, lipids
• Pelvic TV ultrasound

NB. in prolonged amenorrhea, testing can be done on a random day.

🎯 Management Goals

• Correct the underlying cause where applicable
• Support fertility where desired
• Prevent complications e.g.: bone loss / osteoporosis from POI; identify malignancy; address metabolic / endometrial risks in PMOS

🧰 Treatment Options

Management options are tailored to the underlying cause, and may require collaborative endocrinology care. Treatment may involve:

🧘 Functional hypothalamic amenorrhea

• Lifestyle optimisation with adequate calorie intake, reduce excessive exercise if needed, nutritional referral if underweight / restricted eating is present
• Psychology with CBT may help some patients
• Manage bone health when estrogen is low

🥛 Hyperprolactinemia

• Treatment depends on the cause and fertility goals
• Often medication-based

🥚 Primary ovarian insufficiency (POI)

Hormone replacement therapy is indicated up until the age of 50

🧱 Intrauterine adhesions (Asherman)

Typically requires hysteroscopic treatment by a gynaecologist, followed by estrogen to support regrowth

🌀 PMOS

• Treatment depends on patient goals (cycle control, fertility, symptoms)
• Address: oligomenorrhea, hirsutism, obesity and metabolic risk and endometrial protection

🧾 Thyroid disease

Treat the thyroid condition, and menstrual function often improves

🚨 Red Flags

• Seek prompt specialist review
• Refer urgently or prioritise work-up if there are:
  • Headaches with visual disturbances
  • Severe systemic illness or rapid deterioration
  • Very high androgen signs / rapid virilisation

📌 Takeaway

If your periods stop, don’t ignore it: see your women’s health GP, who will take a thorough history and examination, then conduct initial blood test and imaging where indicated. You may require referral to a gynaecologist, endocrinologist or dietician for ongoing collaborative care. Remember there is usually a treatable cause and the correct diagnosis can protect your fertility and long-term health.

🌈 Secondary Amenorrhoea Summary

🎯 1. CONFIRM SECONDARY AMENORRHOEA
• ≥ 3 months no period with regular cycle
• ≥ 6 months no period with irregular cycle

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🤰 2. PREGNANCY TEST — DO THIS FIRST
• Rule out pregnancy

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🧪 3. CHECK SERUM PROLACTIN FOR EVERYONE
• Universal next step

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🧠 4. EVALUATE BY SYSTEM CATEGORY
🌸 Hypothalamus → stress, weight, exercise
🔵 Pituitary → prolactinoma, other lesions
🟣 Ovary → POI, PCOS
💛 Uterus → Asherman’s syndrome

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💡 5. TREAT BASED ON IDENTIFIED CAUSE
• Address underlying condition
• Restore cycles + overall health