Vasomotor

Vasomotor symptom - hot flush is an uncomfortable, subjective feeling of warmth in the upper part of the body

• it affects up to 85% of menopausal women but fewer than half are seriously disturbed by them
• about 20% first notice symptoms while they are still menstruating regularly
• it may be as frequent as every half an hour but more typically, occur 8-15 times a day and the duration varies but averages about 4-5 minutes
• may be accompanied by nausea, sweating that can be profuse and followed by a chill or palpitations, and are particularly troublesome at night, interfering with sleep (1)

Menopausal flushes are of hypothalamic origin associated with the pulsatile release of GnRH. One hypothesis is that flushes involve episodic pulses of dopamine and GnRH together with a "down setting" of central thermoregulatory centres.

For majority of women flushes are transient and slowly improve within a few months (in 30 to 50% of women) and resolves within 4 to 5 years (in 85 to 90% of women) as the body adapts to the new level of oestrogen. But for unknown reasons in around 25%, symptoms persist for more than 5 years. In 90% of cases, exogenous oestrogen or progesterone will relieve symptoms.

Clonidine - which acts directly on the hypothalamus - may also be useful.

Hot flushes seem to have a greater frequency in lower socio-economic classes, in those who smoke, and in thin individuals.

Reference:

• (1) Grady D. Clinical practice. Management of menopausal symptoms. N Engl J Med. 2006;355(22):2338-47.