Although some women are lucky enough not to experience any symptoms at all, the majority of us will have at least one in our perimenopausal years. They are triggered by decreasing levels of estrogen. The hypothalamus is responsible for maintaining body temperature, and the changes to it due to fluctuating estrogen levels lead to hot flushes. Changes in Menstrual Cycles Slight changes in the length of your menstrual cycle may be a sign that perimenopause is beginning. More than three-quarters of all perimenopausal women experience changes in their menstrual cycle.
Cycles can be longer, shorter, or irregular.
They may also be lighter or heavier than they were before. The reason for the irregularities is changes in the body's production of hormones, which occurs as the ovaries run out of eggs. For example, often heavier periods occur when a woman isn't ovulating. During the first half of the menstrual cycle, estrogen levels increase and cause the build-up of the uterine lining. Ovulation at the midpoint of the cycle cues the body to produce another hormone, progesterone, and estrogen production declines.