This time is now commonly referred to as perimenopause and can last for years. Perimenopause begins without symptoms and proceeds to a drop in hormone levels that are significant enough to cause the body to respond by producing hot flashes, changes in periods, some insomnia and mood changes. In addition some women complain of dizziness. Hormone sensitive tissues begin to shrink causing vaginal dryness, and urinary control problems. Bone mass begins to decrease and skin becomes thinner and looses some elasticity.
Hair can become dry, thin and brittle.
It is well worth your time to read about it here. It is unfortunate that this picture of menopause has become one that many women think they must accept. More than 40 million women are menopausal now in America. Within the next 25 years this number is expected to increase to 60 million. At the turn of the 19th century most women did not live past menopause.