What is perimenopause? The overlooked stage prior to menopause

Most people have at least heard of the stage of life when menstrual periods stop, fertility ends and hormone levels permanently decline – the stage of life known as menopause. But far fewer understand the long transitional phase that comes before it.

Known as perimenopause, this period of time can begin years earlier and bring a wide range of physical and emotional changes. Whether such changes are mild and manageable or more disruptive, perimenopause can affect everything from sleep and mood to metabolism and one's sex life.

Understanding what perimenopause is can make a meaningful difference in helping individuals and families navigate it. Here’s what this stage of life is, what causes it and how it’s typically treated.

When does perimenopause start?

Perimenopause is "the transitional phase leading up to menopause," when the body gradually shifts away from its reproductive years, explains Dr. Pelin Batur, medical director of the Cleveland Clinic Women’s Comprehensive Health and Research Center.

Dr. Jewel Kling, associate director of women's health for Mayo Clinic, says menopause "is diagnosed retrospectively after 12 consecutive months without a menstrual period, with no other medical cause." But perimenopause can begin several years earlier, often in a woman's 40s, "though some women may begin to experience symptoms as early as their 30s," says Tina Colella, a certified nurse midwife at Inspira Medical Group in New Jersey.

This stage causes hormonal shifts that can lead to a wide range of symptoms, that Kling says commonly include hot flashes and night sweats; irregular or unpredictable periods; sleep disturbances and fatigue; mood changes "such as irritability, anxiety, low mood;" brain fog or difficulty concentrating; changes in libido and vaginal dryness or sexual discomfort.

"Some women are lucky and have very few symptoms while others may experience a variety of them," says Batur. All women who reach menopause will go through some form of perimenopause and, on average, it's a "stage that lasts four years," he says. For some, it can extend up to a decade. 

What causes perimenopause?

Perimenopause is driven primarily by natural changes in the ovaries. "Women are born with a finite number of eggs in their ovaries, and over time those eggs are gradually depleted," explains Colella. "As this happens, the ovaries produce lower levels of hormones like estrogen and progesterone, initially causing perimenopausal symptoms and eventually leading to menopause."

Several factors can influence when these hormonal changes begin and how perimenopause unfolds, says Kling. For instance, genetics plays a significant role as women often enter perimenopause around the same age their mothers did.

Smoking has been linked to an earlier onset as well, likely because it affects estrogen levels and ovarian function. Certain medical treatments, such as chemotherapy or surgical removal of the ovaries, can also trigger an earlier or more abrupt transition, says Batur. And overall health, body weight and lifestyle factors can shape how symptoms are experienced, even if they don’t directly determine timing. 

How is perimenopause treated?

Treatment for perimenopause is typically focused on managing symptoms and improving quality of life rather than stopping the process itself, notes Colella.

Kling says that for those with moderate to severe symptoms, hormone therapy – often called menopausal hormone therapy (MHT) – is one of the most effective options. This approach usually uses estrogen alone or in combination with progesterone to stabilize hormone levels and reduce symptoms like hot flashes, night sweats and vaginal dryness. In some cases, testosterone replacement therapy may also be considered, particularly for women with clinically diagnosed low levels, as it can help improve sexual function. However, it’s not routinely used for most patients.

For people who cannot or prefer not to use hormones, Colella says that non-hormonal medications such as certain antidepressants or blood pressure drugs may similarly help relieve hot flashes and improve mood symptoms.

At the same time, many lifestyle strategies such as "optimizing sleep, regular physical activity, stress management and limiting alcohol or caffeine consumption can help reduce symptoms on their own," says Kling. Ensuring adequate vitamin D intake, magnesium to help improve sleep or body aches and adequate dietary calcium to support bone health "are all also important," says Batur. "And mind‑body and behavioral therapies such as cognitive behavioral therapy and other structured approaches can also help improve sleep and symptom coping," adds Kling. 

But in the end, Batur emphasizes, "because perimenopause impacts every woman differently, treatment options are individualized according to each patient's priorities."