Most women experience menopause around age 51 but symptoms can start years prior

• Women in the US typically experience menopause around age 51.
• However, menopause-like symptoms often start in the four years leading up to it.
• Smoking, family history, and certain medications can increase your risk of early menopause onset.

Menopause is a normal part of aging that signals the end of your reproductive years. During this time, your ovaries stop producing estrogen, which stops menstruation.

Menopause can happen anywhere between 40 and 58 years of age. However, you'll likely experience symptoms for about four years prior to menopause.

Here's a look at what factors may influence when menopause starts and how long it lasts.

What age does menopause start?

The average age of menopause in the United States is 51 years old, but you may enter perimenopause years in your 40s or 50s, says Felice Gersh, MD, an OB-GYN with Integrative Medical Group.

Medical term: Early menopause is when your period stops sooner than expected. If this happens before 40 it's called primary ovarian insufficiency, which affects about 1% of women ages 30-39.

There are a few different factors that influence when you may enter menopause, including:

• Smoking. People who smoke are more likely to go through menopause sooner and experience more severe symptoms. In fact, a 2012 analysis found a 43% increased risk of menopause occurring before age 50 in women who smoked compared to nonsmokers.
• Family history. If you have a family history of early menopause, you are more likely to experience an early onset too.
• Certain medical conditions, like Turner Syndrome. Turner syndrome is a genetic disorder that affects the X chromosome and can cause ovarian dysfunction, leading to early menopause.
• Surgical removal of your ovaries will lead to menopause but this can be treated with estrogen and/or progesterone replacement or non-hormonal medications. If you have a hysterectomy (when the uterus is removed) but your ovaries are not removed, you will continue to produce estrogen so will not likely experience menopausal symptoms like hot flashes. Much of the treatment plan will depend on the age at which you have your ovaries removed.

There may be other factors that influence menopause onset, but more research is needed to better understand them, says Anna Barbieri, MD, an OB-GYN and founding physician of Elektra Health, a telemedicine provider serving menopausal women.

"For instance, the age at first menstrual period, number of pregnancies, and breastfeeding status may be implicated in reducing the risk of early natural menopause, but more evidence is needed," Barbieri says.

How long does menopause last?

Menopause is permanent and marked by no menstrual bleeding for 12 consecutive months. However, the symptoms that are typically associated with menopause actually occur in the eight to 10 years before your final period, Gersh says.

This time frame is called perimenopause and it's when your body starts to decrease estrogen production and your ovulation becomes more inconsistent, which can lead to physical symptoms, including:

• Irregular periods
• Hot flashes, which affect an estimated 35% to 50% of perimenopausal people
• Vaginal atrophy, or vaginal dryness
• Pain during sex due to vaginal dryness
• Mood swings
• Difficulty sleeping, which affects about 40% of perimenopausal people
• Dry skin
• Thinning hair
• Night sweats

Symptoms of perimenopause are usually the worst in the first two years, says Zaher Merhi, MD, an OB-GYN, reproductive endocrinologist, and founder of the Rejuvenating Fertility Center.

And symptoms will usually continue through menopause, but fade about a year after your last period. However, this too can vary and some people experience ongoing symptoms for years after their periods end due to fluctuating estrogen levels.

In fact, a 2015 study examining the duration of menopausal symptoms in women ages 42 to 52 found that vasomotor symptoms, such as hot flashes, persisted for 4.5 years after their final menstrual period.

Insider's takeaway

Menopause can happen anytime between the ages of 40 and 58, but the average age for menopause in the US is 51.

However, you may experience symptoms like hot flashes or mood swings in the eight to 10 years leading up to menopause. This time period is known as perimenopause and it marks when your body starts producing less estrogen.

If perimenopausal symptoms like vaginal dryness or hot flashes are impacting your life, talk with your doctor. There are ways to treat and manage these symptoms, such as hormone therapy or non-hormonal medication.