Some women find the end of monthly periods a cause to celebrate—no more hassling with tampons; no more pregnancy scares. Others feel sad. For them, menopause signals the end of the reproductive years and what some view as the start of life's sunset.

For others, menopause arrives abruptly and without warning. Their periods simply cease. But most women endure a phase of erratic periods before they finally come to an end. This transition period—which can last for several years—is called perimenopause. When the number of eggs in a woman's ovaries becomes low as a result of decreasing levels of the female hormones—estrogen and progesterone—menopause occurs.

Regardless of how you feel about menopause-whether you're looking forward to it or dreading it—here is what you can expect, by the numbers:

  • 6 months to 6 years: The length of time perimenopause typically lasts, culminating a year after the final menstrual period.
  • 7 or more: Number of days an irregular period lasts.
  • 8: Percentage of women who undergo menopause before the age of 40.
  • 10: Number of common symptoms created by falling estrogen levels:
    1. Irregular or missed periods
    2. Hot flashes/night sweats (which interfere with sleep)
    3. Anxiety/depression/mood swings
    4. Vaginal dryness which may cause pain during intercourse
    5. Loss of sexual desire
    6. Thinning hair/facial hair growth
    7. Frequent urination or leakage
    8. Headaches and backaches
    9. Pounding heartbeat/dizziness
    10. Loss of sleep (which can contribute to fatigue, mood disturbances and cognitive impairment)
  • 12: Number of months a woman misses her period to receive a clinical diagnosis of menopause. When the diagnosis is unclear, a test to measure follicle—stimulating hormone (FSH) can provide information about estrogen levels. As estrogen levels decrease FSH levels increase in an attempt to get your ovaries functioning again.
  • 20 to 25: The percentage of women who receive prolonged treatment for severe menopause symptoms.
  • 30: Age that women reach their peak bone mass density. Menopause can accelerate the loss of bone mass since estrogen helps maintain bone thickness. Calcium, vitamin D, exercise, and hormone replacement therapy can slow bone loss. Thin bones are fragile and can become injured or break more easily.
  • 30 or more: The number of years women in the U.S. can expect to live in the postmenopausal state.
  • 51: The average of age of the onset of menopause in the U.S. according to the North American Menopause Society. However, the age of menopause varies quite a bit and some experts believe that your mother's age at menopause is the best predictor of what your age will be.
  • 60: The number of days a woman goes without having a period which signals she has entered late menopause transition, according to the Hormone Health Network.
  • 60: The percent of women who visit a doctor to discuss their menopause symptoms.
  • 60 and younger: The age at which it is safest for women to receive Menopausal Hormone Therapy (MHT), formerly known as hormone replacement therapy or HRT. MHT can alleviate menopause symptoms and is not safe for women over 60, according to research conducted through the Women's Health Initiative and the National Institute of Aging.
  • 75: percentage of menopausal women in the U.S. who experience hot flashes. If you suddenly feel warm, start to sweat, and get red in the face, you are likely having a hot flash. It's not unusual to feel cold and clammy after a hot flash.
  • 30 seconds to 10 minutes: The length of time a hot flash typically lasts. When/if they occur at night, hot flashes can disturb you from a deep sleep.
  • 2 million: Number of eggs a woman is born with. Women do not make eggs during their lifetime.
  • 400,000: average number of eggs in the ovaries of an 18-year-old female.
  • 25,000: average number of eggs in the ovaries of a 37-year old female.
  • 300: approximate number of eggs in a woman's ovaries as she approaches menopause.




The North American Menopause Society (NAMS)

Expert Answers to Frequently Asked Menopause Questions
Menopause Basics

The American College of Obstetrics and Gynecologists

Epigee Women's Health
Irregular Periods (Oligomenorrhea)

Hormone Health Network
Menopause Symptoms

National Institute on Aging
Hormones and Menopause