Predicting—accurately—how long your menopausal transition is likely to last and when you’ll reach menopause is extremely challenging, if not impossible. There are several factors, however, that may help you narrow down the time frame, such as knowing the average age of menopause, and when your own mother experienced it. Here’s an overview of what can affect your age of menopause, and why you might want to know when to expect it.

The World Health Organization places the average age of menopause globally betweenAccording to the North American Menopause Society, many women in the United States reach menopause between ages 40 and 58, with the average age being 51. Since perimenopause can last for several years, this means that most women begin to experience hormonal changes and their accompanying symptoms in their late-30s to mid-40s. These symptoms can include:

• Hot flashes and night sweats
• Insomnia or difficulty staying asleep
• Achy joints and muscles
• Dry, itchy skin
• Thinning skin and hair
• Heart palpitations
• Mood swings, anxiety, and depression
• Loss of vaginal lubrication
• Irregular periods

Most of these symptoms will stop once you reach menopause, which is defined as having gone for at least 12 months without having a period.

Having some idea of when you might reach menopause is important because the loss of estrogen, which is at the core of menopause, also causes other changes to your body that can impact your health in dramatic, and sometimes harmful, ways.

• Bones can weaken, become brittle, and break or fracture more easily.
• Cholesterol and blood pressure can increase, raising the risk of heart disease.
• Less collagen is produced, meaning thinner skin that tears more easily and heals more slowly.

Having early or late menopause can predict certain health issues, to some degree, says Stephanie S. Faubion, M.D., the director of the Office of Women’s Health at the Mayo Clinic in Jacksonville, Florida.

She explains that early menopause (occurring before the age of 40) has been linked to “a higher risk of osteoporosis and fracture, heart disease, cognitive impairment and dementia, and early death.”

For these reasons, later-onset menopause may be considered healthier, but late-onset has been associated with its own risks, including a greater likelihood of developing breast, ovarian, or endometrial cancer.

Knowing what health challenges you might face, and when you might face them, can help you prepare and make informed decisions.

Several factors can influence the age at which you’re likely to reach menopause, among them:

• Genetics,
• Underlying medical conditions, and
• Race.

“When we look at the things that are the greatest determinants for when someone is going to go through menopause, genetics seems to be one of the most important things,” says Lauren Streicher, M.D., a clinical professor of obstetrics and gynecology, and medical director of the Northwestern Center for Menopause in Chicago. “I always ask women…‘When did your mom go through menopause?’ because that is very often predictive.”

Underlying medical issues can bring on early menopause. These issues can include autoimmune conditions like lupus and thyroid hormone imbalances.

Race can also affect your age of menopause. According to the Study of Women’s Health Across the Nation (SWAN), Black women experience perimenopause and menopause at younger ages.

According to Faubion, natural menopause prior to age 40 occurs in approximately 1- 2% of women. “Experiencing menopause at 40 to 45 years of age is called early menopause, and that occurs in about 5 to 7 percent of the population, so it’s safe to say that at least 7 percent of women are going to go through menopause early or prematurely,” she writes, adding that experiencing menopause at 46 or older is considered normal.

Research studies have suggested several other factors besides genetics, medical conditions, and race that may influence the age at which you reach menopause. These include:

• The age at which you begin perimenopause. Although it may be difficult to pinpoint when you begin perimenopause, at least one study has shown that starting perimenopause at a younger age meant a longer transition period.
• A shorter menstrual cycle. Another study indicated that women with menstrual cycles lasting fewer than 25 days were more likely to reach menopause earlier than women with 26- to 34-day cycles.
• Smoking. Women who smoke have been seen to reach menopause earlier than nonsmokers.
• Pregnancy and breastfeeding. The results of one study suggested that women who bear children and breastfeed may have a lower risk of early menopause. Not all experts concur, however.
• Sexual activity. In one study, women who reported having more frequent sex were more likely to reach natural menopause at a higher age.
• Experiencing trauma. Physical and/or sexual childhood trauma, in both a woman and her child, can result in earlier menopause. Chronic stress is thought to suppress the immune system and affect the release of certain hormones. This is referred to as the ‘weathering hypothesis’. The cumulative burden of chronic stress and traumatic events is called ‘allostatic load’.

Menopause, typically early menopause, can also occur as a result of chemical or surgical interference with the natural decline of sex hormones.

Chemotherapy, for instance, can be toxic to the ovaries. Women who undergo chemotherapy often experience temporary menopause. Though menstrual cycles usually (though not always) return within two years of stopping chemo, natural menopause will likely occur several years earlier than it would have without chemotherapy.

Women who undergo the surgical removal of their ovaries (oophorectomy) experience immediate menopause, since the body’s primary source of estrogen and progesterone are gone. Younger women who have this surgery are usually placed on hormone replacement therapy, to maintain the protective benefits that their natural hormones would have provided for several more years, if not several more decades.

Experts say that, as with women who experience natural menopause within a normal time frame, women who experience early-onset menopause should be monitored for health risks such as higher cholesterol and blood pressure, bone mineral loss, and heart disease.