↓ Ovarian function from age-related ovarian follicle loss leads to:
↓ Estrogen and progesterone levels → loss of negative feedback on the pituitary gland → ↑ GnRH levels → ↑ FSH and LH levels (hypergonadotropic hypogonadism)
↑ In anovulatory cycles
As the ovaries age, they become less responsive to gonadotropin stimulation.
Ovarian function eventually ceases.
Iatrogenic removal of the ovaries leads to abrupt cessation of ovarian function.
Vasomotor symptoms
Hypothalamic thermoregulatory zone narrows → small temperature changes trigger compensatory reactions
↓ Estrogen is associated with ↑ norepinephrine and ↓ serotonin
Genitourinary symptoms
Hypoestrogenism → vaginal and vulvar epithelial atrophy, as well as urethral and bladder atrophy
Estrogen has positive effects on collagen and the epithelial surface.
Clinical features
Menstrual abnormalities
Irregular menses that gradually decrease in frequency until complete amenorrhea
Vasomotor symptoms of menopause (VMS)
Increased sweating
Hot flashes
Heat intolerance
Seen in ∼ 75% of individuals during perimenopause and menopause
On average, vasomotor symptoms last for ∼ 7 years.
Other symptoms
Osteoporosis
Develops at least 10-15 years after cessation of menses
Diagnostics
Supportive studies to confirm menopause
FSH: ↑↑; however, levels widely fluctuate during perimenopause
Estradiol: ↓
Rarely tested for as not routinely recommended: ↓ progesterone, ↓ inhibin B, and ↓ antimüllerian hormone
Studies to exclude differential diagnoses of menopause
Pregnancy test: to rule out pregnancy as a cause of amenorrhea