For many individuals, the first noticeable sign of perimenopause is a change in the menstrual cycle. Periods may become irregular, with the time between them becoming shorter or longer than usual. A persistent difference of seven or more days in the length of consecutive cycles is a hallmark of the early menopausal transition. It is also common to notice changes in menstrual flow, which could become heavier or lighter than what was previously the norm. While these irregularities are an expected part of the transition, it is important to consult a doctor for any very heavy bleeding or any bleeding that occurs after menopause has been established, in order to rule out other underlying health issues.