Definition — No period for 3 months (for 6 months if periods always irregular & spaced out)
- Doesn’t count women using birth control methods which commonly cause amenorrhea
- Assuming patient is not pregnant (pregnancy test is always first step in diagnosis)
Causes of Amenorrhea
| xxxCommon Causes (>90% of cases) | xxxxxxUncommon Causes |
|---|---|
| โข “Functional“ * โข Polycystic Ovarian Syndrome (PCOS) ** โข Conditions of the Brain (Hypothalamus and xxxxPituitary Gland) โข Premature Ovarian Failure (Premature xxxxMenopause) x | โข Hyperthyroidism / Hypothyroidism โข Celiac Disease โข Type-1 Diabetes โข Various Tumors (brain, pituitary gland, ovary) โข Scars in Uterus (from surgery; or severe xxxxbleeding during childbirth) โข Congenital Adrenal Hyperplasia (CAH) ** |
Most Common Causes
** ย “Functional” Amenorrhea — due to eating disorders, malnutrition, excessive exercise (running, ballet, gymnastics, figure skating), severe physical or psychological stress
** Polycystic Ovarian Syndrome (PCOS) — excess facial / body hair, scalp hair loss, acne; & obesity. Similar body characteristics also with Congenital Adrenal Hyperplasia (CAH); but PCOS is much more common.
Premature Ovarian Failure — Menopause occurs too soon, usually for reasons nobody knows
Diagnostic Work-Up of Amenorrhea
Initially — Pregnancy Test.ย If negative, then:
1. Look for signs of PCOS. If present, blood test for Testosterone & maybe other male hormones.
2. Blood Tests: TSH (thyroid test), Prolactin, FSH & Estradiol (female hormones).
Diagnosis & other Work-Up
- Abnormal TSH ย โ Thyroid Disease (Hyperthyroid or Hypothyroid)
- Elevated Prolactin (repeat a 2nd time too) โ maybe Pituitary Gland tumor ย โ brain MRI
- Elevated FSH (maybe low Estradiol; hot flushes, vaginal dryness) โ Premature Ovarian Failure [if very young for Premature Menopause, refer to Gynecology to rule out rare causes]
- All labs normal & symptoms of PCOSย ย โ ย diagnose PCOS (esp. if elevated level of Testosterone; if very elevated, refer to Endocrinology to rule out rare tumors)
- Might order 17-hydroxyprogesterone level (early morning) for CAH [rare]
- All labs normal except maybe low Estradiolย ย โ ย test for Diabetes Type-1 and Celiac Disease.ย If those tests negative:
- if history of factors that cause “Functional” Amenorrheaย ย โย that’s the diagnosis
- if no such factorsย ย โ ย brain MRI to rule out Pituitary Gland Tumor
- if history of uterine surgery or severe bleeding after childbirthย ย โ ย try to induce a period with hormone pills.ย If no period, refer to Gynecology to examine for uterine scars (adhesions)
See Amenorrhea โ Full Text for more in-depth explanations and discussions.