Hot flashes? Wild mood swings?

Anita McCallum, 48, was sitting in her car one day when she began to menstruate so heavily, it soaked through her clothes and into the upholstery of the car. It happened with no warning and no time to prepare. "I was hemorrhaging uncontrollably," she recalls. The incident left her severely shaken for several days afterward.

Anita is in the throes of perimenopause, a hormonal upheaval that signals impending menopause. Those unpredictable periods, as well as other physiological symptoms such as mood swings, night sweats and vaginal discomfort, could occur for years before the "change" finally arrives.

The age-related transition from fertility to infertility can begin as early as the mid-30s, but for most, signs of perimenopause become apparent in the early to mid-40s. Generally the symptoms continue for five to seven years before menstruation ceases altogether and menopause begins, usually around age 51.

Some women simply sail through this time of transition. Many don't. Like Anita, they grapple every month with a myriad of annoying and sometimes painful symptoms.

Perimenopause has become a recognized health entity just in time for the baby boomer bulge to move through the so-called prime of life - the fabulous 40s - and into life's second act. Ten years ago, a woman complaining of menopausal symptoms before reaching her 50s was more often than not dismissed as being too young for intervention. Today, doctors listen carefully to women's perimenopausal complaints and prescribe appropriate relief. Meanwhile, perimenopause is attracting increasing attention from researchers, physicians, psychiatrists, counsellors and others.

Causes
While there is some debate about what exactly is happening to a woman's body during perimenopause, what is clear is that the ovaries are beginning to gear down their egg production. As they do, the delicate balance of the female hormones estrogen and progesterone is thrown off kilter.

Both hormones are produced by the ovaries and work together with intricate timing to orchestrate ovulation and to complete the menstrual cycle. "We used to think that estrogen levels gradually dwindled as the reproductive capability of the ovary waned," explains Dr. Suzanne Montemuro, a family doctor and the director of the North Shore Menopause Information Centre in Vancouver. "But we're beginning to think that perhaps there is a surging as well as a falling of hormones."

She compares perimenopause to adolescence, when the reproductive system is gearing up and teens experience erratic periods and raging hormones as the body adjusts to the reproductive cycle. "In perimenopause, the system is gearing down and the same thing seems to be happening," she says. "Overall, the hormone levels are going to fall but they seem to be doing so in a sporadic fashion."

Signs
The result of all this hormonal activity is wacky menstrual periods that can become more or less frequent and may be heavier or lighter than usual.

At the same time, premenstrual syndrome (PMS) with its mood swings, bloating and breast soreness, may take on a new intensity and may coexist with other signs of menopause, such as hot flashes, night sweats, sleep disturbances, memory changes, fatigue and headaches.

Many women also complain that perimenopause exacerbates other medical conditions they may have, such as arthritis or fibromyalgia. The reasons are unclear, but the stress of perimenopause and lack of sleep may impair coping skills and make all problems appear worse, say specialists.

An annoying twist to this scenario is the unpredictability of any or all of the perimenopausal symptoms. Constant change is the hallmark of perimenopause. Every month may be different from the last one.

Learn more about the symptoms of perimenopause.