Vasomotor Symptoms of Menopause: Overview and Risk Factors
At menopause, a woman's ovaries stop producing eggs, her body produces less estrogen and progesterone, and menstrual periods become less frequent, eventually stopping altogether. The mean age of menopause in normal women in the United States is 51. Menopause that occurs beyond age 56 is considered late menopause.
A perimenopausal transition generally occurs for several years prior to the cessation of menstruation. During this time, the ovulatory cycle is often erratic, resulting in irregular menses, heavy breakthrough bleeding, hot flashes, and vaginal dryness.
Upon cessation of ovarian follicular function, production of estrogen declines and production of gonadotropin (follicle–stimulating hormone, luteinizing hormone) rises. The decrease in circulating estrogen results in the clinical symptoms of menopause.
Hot flashes are the most common initial menopause symptom, occurring to some extent in up to two thirds of North American women. This phenomenon may be due to estrogen withdrawal and consequent bursts of gonadotropin–releasing hormone from the hypothalamus, which can affect the nearby thermoregulatory center in the brain. A sensation of heat and perspiration may last several minutes and is often preceded or followed by chills and shivering. In some cases, palpitations accompany these symptoms.
Vaginal dryness, due to the decrease in estrogen stimulation of the vagina and urethra, is common and may cause dyspareunia.
Psychological distress may occur, including depression, anxiety, irritability, fatigue, and difficulty concentrating. These symptoms may reflect the contributions of hormonal shifts and the sleep disturbances associated with hot flashes, which can be improved by any measures that improve sleep.
About 40% of North American women seek treatment for menopausal symptoms. There are some suggestions that African American women are less likely to report symptoms compared with Caucasians. Risk factors for the development of menopausal symptoms are poorly defined, but are likely related to a combination of environmental, lifestyle, and social factors. No consistent evidence has linked weight, health status, and hysterectomy with vascular symptoms of menopause. Symptoms appear to be significantly less common in Asia, compared with North America, a difference that has been attributed to diet.
Vasomotor Symptoms of Menopause: Assessment and Treatment >>