8.1 Diagnosis of Menopause

Natural menopause in a woman > 45 years of age is diagnosed retrospectively following 12 months of amenorrhea  and is associated with elevated gonadotrophins and oestrogen deficiency. The diagnosis of menopause secondary to bilateral oophorectomy is obvious. However, the diagnosis of spontaneous menopause in younger women is often difficult (See Early Menopause Website - diagnosis). The onset of amenorrhea/ menopause may occur abruptly or insidiously and return of menstrual function (which may be transient) may be observed following chemotherapy, particularly in younger women. In a prospective cohort study of women aged 20-45 years with breast cancer, only 40% of women reported monthly menstrual bleeding at the end of chemotherapy rising to a peak of 55% at approximately 15 months post diagnosis and then declining to 35% of women at 5 years. 

The diagnosis of the menopausal transition in a woman older than 45 years with menstrual disturbance and vasomotor symptoms is usually clinical.  Fluctuating gonadotrophin and oestradiol levels with ovulatory and anovulatory menstrual cycles are common and therefore hormone measurements are rarely useful (see Physiology Table : Changes across the menopause transition from pre- to postmenopause). 

8.2 Diagnosis of early/ premature menopause 

(see Early Menopause Website - diagnosis) 

The commonly used diagnostic criteria for premature menopause are shown below (see Early Menopause Website - laboratory investigations). Menopausal symptoms, including vasomotor symptoms, may/ may not also be present. It is important to remember that women taking the oral contraceptive pill have an artificial withdrawal bleed which does not reflect the natural menstrual pattern. Gonadotrophin and oestradiol levels cannot be accurately assessed while a woman is taking the oral contraceptive pill which must be withdrawn for at least one month prior to hormone measurements. Tamoxifen use may also be associated with un-interpretable reproductive hormone levels. 

Table: Diagnostic criteria for premature menopause

 8.3 Differential diagnosis of hot flushes

The differential diagnosis of flushing is shown in Table : Differential diagnosis of flushes. More than 600 drugs and 300 drug interactions have been implicated as a cause of flushing ( see Table : Commonly used drugs causing flushes). Clinical assessment is directed at establishing the diagnosis and excluding uncommon but potentially life threatening disorders. History and physical examination are critical in the evaluation of the cause of flushing. History should focus on the anatomical location of the flushes, temporal characteristics, provocative and relieving factors, any associated symptoms and medication. A flush diary is often useful. A “wet” flush is associated with sweating and suggests autonomic activation whereas a “dry” flush (no sweating) suggests direct vasodilatation. Physical examination may reveal characteristic signs such as urticaria pigmentosa (mastocytosis), thyroid nodule (medullary carcinoma of the thyroid), hypertension (phaeochromocytoma) and right sided valvular heart disease (carcinoid). Investigations, including laboratory and imaging, are based on clinical suspicion and assist in confirming (or excluding) the diagnosis.

Table: Differential diagnosis of flushes.

Table: Commonly used drugs causing flushes

References:

• Izikson L et al., The flushing patient: Differential diagnosis, workup and treatment. J Am Acad Dermatol 2006; 55:193-208.
• Nelson LM . Primary Ovarian Insufficiency. New Engl J Med (2009) 360:606-614
• Pektek JA, Naughton MJ et al., Incidence, time course and determinants of menstrual bleeding after breast cancer treatment: a prospective study. J CLin Oncol (2006) 24: 1045-1051.

9. Long term consequences

Content updated December 2010