Perimenopause is the transitional phase leading up to menopause, and it can bring a whirlwind of physical and emotional changes. For many women, it begins in their 40s, though it can start earlier, and it’s marked by fluctuating hormone levels that can cause a variety of symptoms.
If you’ve been noticing changes in your cycle, mood swings or unexpected physical shifts, such as interrupted sleep, hot flashes or joint paint, to name a few, you might be entering this phase. But how do you know for sure?
Understanding the key signs of perimenopause can help you navigate this period with greater clarity and confidence. Here’s what you need to know.
Irregular periods
One of the hallmark signs of perimenopause is changes in your menstrual cycle.
“Perimenopause symptoms often present as irregular periods and fluctuations in hormone levels,” Dr. Meleen Chuang, chief of obstetrics and gynecology at NYU Langone Hospital Brooklyn, tells Flow Space. “Menopause is defined only when the menstrual cycle stops for one year. Symptoms of menopause may be similar but can be more pronounced, like persistent hot flashes and vaginal dryness.”
The reason why periods can become irregular during perimenopause is due to fluctuating hormone levels, particularly estrogen and progesterone. As the ovaries gradually produce less estrogen, the menstrual cycle becomes more erratic. Another reason is that ovulation becomes irregular. During perimenopause, ovulation (the release of an egg from the ovary) may not occur every month.
Without consistent ovulation, progesterone levels drop, and this can lead to periods that are irregular in timing, length and flow. Some women might also experience heavier periods during this time, with up to 90% of women experiencing abnormal bleeding, according to data published in the National Library of Medicine.
Dr. Mindy Goldman, chief clinical officer at Midi Health, explains that during perimenopause, it’s common to go months without a menstrual cycle. However, the ovaries continue to produce estrogen, which causes the uterine lining to build up and thicken over time.
“Eventually, ovulation occurs and progesterone is produced and stabilizes the lining,” Goldman says. “But this time, when the progesterone levels fall and the lining sheds, there is a much thicker lining so the menstrual period is much heavier.”
Mood swings and emotional shifts
Fluctuating hormones can also impact your mood. You might notice increased irritability, anxiety or bouts of sadness that seem to come out of nowhere. About four in 10 women report having mood symptoms during perimenopause, according to data from the American College of Obstetrics and Gynecology. During this time, many women report feeling more emotionally sensitive or having mood swings similar to those experienced during PMS.
It’s all part of the hormonal rollercoaster of perimenopause.
One of the reasons why women experience mood swings during this time is due to how estrogen influences serotonin, a neurotransmitter that regulates mood. Estrogen levels rise and fall unpredictably during perimenopause, which can affect serotonin production and lead to feelings of irritability, anxiety or sadness.
Another culprit is progesterone, which has a calming effect on the brain. As ovulation becomes irregular, progesterone production decreases and can lead to heightened emotional sensitivity or mood swings.
Hot flashes and night sweats
Most perimenopause symptoms will look similar to the ones women experience during menopause, and hot flashes are a big one. If you’re going through perimenopause, you may experience sudden, intense waves of heat that can last for seconds or minutes, often accompanied by sweating and a flushed face. Night sweats can disrupt your sleep, leaving you feeling fatigued the next day.
Dr. Bruce Dorr, an OB-GYN and senior medical advisor to Biote, says women often report that hot flashes feel like a sudden warmth coming from the shoulders up. Chills and night sweats that are heavy enough to soak your pajamas and blankets often accompany hot flashes.
Sudden, unexplained weight gain
In addition to the internal changes, you may notice physical shifts such as weight gain, particularly around your abdomen, thinning hair or dry skin. These changes are also tied to hormonal fluctuations —and while frustrating—they’re a natural part of this transition.
Estrogen plays a role in regulating metabolism and fat distribution, so lower levels can lead to a shift in where and how fat is stored.
“The depletion of estrogen has been shown to be linked to an additional 1.5 pounds of weight gain per year—independent of other weight gain that comes with age,” Dr. Kathleen Jordan, chief medical officer for Midi Health says. “This weight gain also shifts to be central weight gain—or belly fat. Belly fat in general is associated with more negative health outcomes.”
Decreased libido
Some women might experience a decrease in sexual desire during perimenopause, often due to changing hormone levels, increased stress or vaginal dryness. This can be a sensitive subject, but it’s important to know that it’s a common part of the process. A 2019 research review found that sexual function often starts to decline about 20 months before your final period.
Though often associated with men, testosterone levels also plays a big role in women’s sex drive. Testosterone, which women produce naturally but in much smaller quantities than men, declines with age, most often contributing to a reduced libido.
However, for some women, lower estrogen and progesterone levels can actually make testosterone’s effects more noticeable, which can boost libido instead. While possible, it’s more likely that vaginal tissues will become thinner, drier and less elastic—due to estrogen levels dropping—leading to discomfort or pain during sex, which can decrease sexual desire
Can perimenopause be confused for another condition?
It’s very easy to mistake perimenopause for other conditions due to overlapping symptoms.
“Sometimes perimenopause can be confused with other conditions like thyroid disorder, endometriosis and polycystic ovary syndrome (PCOS),” Chuang says. “This happens because these conditions may exhibit symptoms similar to perimenopause due to hormonal imbalances.”
For example, hypothyroidism and hyperthyroidism can cause symptoms like fatigue, mood changes and irregular periods, which are similar to perimenopause. Same goes for PCOS, which can also cause irregular periods and hormonal imbalances, and may look similar to perimenopause in some women.
Chuang explains that certain factors, such as autoimmune diseases, poor overall health or being underweight, can increase the likelihood of experiencing perimenopause earlier than usual. For women experiencing conditions like lupus or thyroid disorders, the immune system can mistakenly attack the body’s tissues, including the ovaries. This can disrupt ovarian function, leading to lower estrogen production and an earlier onset of perimenopause.
“Other risk factors such as genetics, smoking and certain medical treatments like cancer therapy can cause earlier onset,” Chuang says.
When should you see a doctor?
Women should be proactive and start discussions with their healthcare providers in their 40s, even before symptoms begin. Doing so could make the perimenopause journey more manageable. If you’re unsure whether or not your symptoms are related to perimenopause, it doesn’t hurt to get a second opinion from a medical professional. Just make sure it’s someone trained in menopausal care.
About “80 percent of residency programs that are training OB-GYNs don’t have any education in menopause, and for the majority of the 20 percent of programs remaining, that education is only elective,” says Dorr. He recommends asking your healthcare specialist what they know about hormone replacement therapy and finding a new doctor (the Menopause Society allows you to search for Menopause Society Certified Practitioners, or MSCPs, via country or zip code), if that’s something they don’t prescribe.
A menopause specialist stays up-to-date on the latest professional resources to help improve women’s health during the menopause transition and beyond, and an appointment generally includes a physical check-up, taking a medical history of your last few menstrual cycles and gaining an understanding of when your symptoms first began. They may also perform a blood test to measure your hormone levels.
Seeing a doctor for perimenopause is also helpful if you’re not finding relief on your own or if symptoms become so severe they affect your quality of life. Your healthcare provider may recommend systemic estrogen therapy. This hormone treatment—which includes low-dose birth control pills, skin patches, gel or cream—can help manage the discomfort that comes with night sweats and hot flashes. The vaginal ring and cream have also show to help find relief against vaginal dryness.
“Make an appointment with your OB-GYN, if you have painful menses, irregular bleeding, believe onset is too early or worried about not being able to conceive,” Chuang says. “Your OB-GYN can draw labs and give you a sense of what is going on.”