Perimenopause—the transitional phase leading up to menopause—can feel like a time of upheaval, both physically and emotionally. If you’re in perimenopause, you might find yourself dealing with a variety of symptoms that seem to come out of nowhere: irregular periods, hot flashes, mood swings, sleep disturbances, and more. Some days, it may feel like your body is no longer working the way it used to, leaving you feeling frustrated, confused, or even a little bit lost.

What’s really happening in the body during perimenopause? And why are all these changes happening to you at once? Understanding the science behind perimenopause can shed light on the myriad physical, mental, and emotional changes you’re experiencing. Let’s take a closer look at a typical day in the life of someone going through perimenopause and explain why things are happening the way they are.

Morning: Waking Up to Fatigue and Hot Flashes

The alarm goes off, and you wake up already feeling tired—more so than you did before. Despite having a full night’s sleep, you feel like you’ve been up all night. Maybe your sheets are damp with sweat or you’re feeling an intense flush of heat, and your heart is racing. This is one of the hallmark symptoms of perimenopause: the hot flash.

Physically: During perimenopause, your ovaries gradually produce less estrogen and progesterone, two hormones that regulate your menstrual cycle and play a role in other bodily functions, including sleep, mood, and temperature regulation. As estrogen levels fluctuate, they can cause changes in your hypothalamus, the part of the brain responsible for regulating body temperature. This leads to the sudden, intense hot flashes that can cause you to feel overheated, sweat profusely, or experience heart palpitations. These can occur at night as well, leading to night sweats, which disrupt your sleep and leave you feeling exhausted in the morning.

Mentally: The hormonal fluctuations can affect brain function too. You may find it harder to focus in the morning, and simple tasks might feel more challenging. Memory lapses, confusion, or difficulty concentrating—often referred to as "brain fog"—are common during perimenopause. This is partly because estrogen also influences neurotransmitter systems involved in mood, cognition, and memory, such as serotonin and acetylcholine. Low estrogen levels can lead to difficulties in concentration and an increased risk of mood swings.

Mid-Morning: The Energy Slump

By mid-morning, you’re feeling the familiar energy slump. Your brain might still be a little foggy, and you're fighting the desire to nap or at least take a break. You might be wondering how long this fatigue will last.

Physically: During perimenopause, the fluctuations in estrogen and progesterone can affect your energy levels. Lower levels of estrogen can lead to a slower metabolism, making you feel more sluggish and fatigued throughout the day. Progesterone, which also decreases during this time, has a calming, sedative effect, so when levels drop, you might feel less able to cope with the demands of daily life. Your body’s circadian rhythm, which regulates sleep and wake cycles, can also be disrupted by hormonal shifts, further contributing to daytime fatigue.

Mentally and Emotionally: The drop in estrogen can also affect the production of key neurotransmitters in the brain that regulate mood, such as serotonin. This can make you more susceptible to feelings of irritability or sadness. You might feel easily overwhelmed or experience more emotional highs and lows than usual. Emotional regulation can become a bit more difficult, leaving you feeling like you're on an emotional rollercoaster.

Afternoon: The Emotional Rollercoaster

As the day continues, your emotions might start to feel a little all over the place. One minute you’re fine, and the next, something small might trigger a wave of anger, frustration, or even tears. These emotional ups and downs are another feature of perimenopause.

Physically: Again, the fluctuations in estrogen and progesterone are to blame. Estrogen has a direct impact on serotonin, a neurotransmitter that helps regulate mood, while progesterone has a calming effect on the brain. As estrogen levels fluctuate during perimenopause, it can lead to mood swings, irritability, anxiety, and depression. The decline in progesterone can also result in heightened emotional sensitivity. With this hormonal rollercoaster, it’s not uncommon for someone going through perimenopause to experience feelings of frustration or sadness with little warning.

Mentally and Emotionally: These emotional swings can be disorienting. You might find yourself feeling like you don’t have control over your emotions. It's also common to experience anxiety about the future—whether that’s related to aging, body changes, or concerns about menopause itself. This emotional turbulence can leave you feeling vulnerable or less like yourself. It's important to remember that these mood swings are a natural part of the perimenopausal process, but that doesn't make them easy to navigate.

Evening: Difficulty Unwinding and Sleep Disruptions

By the time evening arrives, you’re exhausted, but winding down for bed feels difficult. Despite the fatigue, your mind is still racing, and you may have trouble falling asleep. Maybe you’ve experienced hot flashes again, or you’re feeling restless and jittery, making it hard to get comfortable.

Physically: One of the main culprits behind sleep disturbances during perimenopause is the drop in progesterone, which has a natural sedative effect. As progesterone decreases, it can make falling asleep more difficult, and staying asleep can become a challenge. Hot flashes and night sweats, caused by the hormonal fluctuations of perimenopause, can also disrupt sleep, leading to frequent awakenings during the night. This lack of restful sleep compounds the daytime fatigue, creating a vicious cycle of exhaustion.

Mentally and Emotionally: Sleep deprivation can take a heavy toll on emotional health, further exacerbating feelings of irritability, stress, and sadness. The anxiety that builds throughout the day can make it even harder to unwind, leading to feelings of frustration and helplessness as you lie in bed, wide awake. Emotional regulation becomes even more difficult without a good night’s sleep, making it feel like a constant struggle.

The Science Behind Perimenopause

Perimenopause is the time in a woman's life leading up to menopause, usually beginning in the late 30s to early 40s, and lasting until menopause (when a woman has not had a period for 12 consecutive months). This phase is marked by fluctuating hormone levels, particularly estrogen and progesterone. These fluctuations and declines lead to the wide range of symptoms women experience during this time, including:

1. Hormonal Fluctuations: Estrogen and progesterone, which regulate the menstrual cycle, begin to fluctuate. These shifts can cause irregular periods, hot flashes, night sweats, and vaginal dryness.

2. Hot Flashes and Night Sweats: The decrease in estrogen impacts the hypothalamus, the part of the brain that controls temperature regulation. This leads to hot flashes—sudden feelings of intense heat—and night sweats, which are hot flashes that occur during sleep.

3. Sleep Disruptions: The drop in progesterone and fluctuating estrogen levels make it harder to fall asleep and stay asleep, contributing to night sweats and restlessness.

4. Mood Swings and Anxiety: Lower estrogen levels can lead to decreased serotonin production, affecting mood regulation and making emotional stability more difficult.

5. Brain Fog and Cognitive Changes: Estrogen plays a role in brain health, including cognitive function and memory. As estrogen levels decrease, some women experience difficulty with concentration, memory, and focus, leading to “brain fog.”

Coping with Perimenopause

Living through perimenopause can be challenging, but there are ways to manage the symptoms and take control of your health:

1. Hormone Replacement Therapy (HRT): HRT can help alleviate many of the symptoms of perimenopause by replacing the hormones that are declining in your body. This can help with hot flashes, sleep disturbances, and mood swings.

2. Lifestyle Modifications: Regular exercise, a balanced diet, and stress management techniques like yoga, meditation, or deep breathing exercises can help stabilize mood and improve energy levels.

3. Sleep Hygiene: Establishing a calming nighttime routine and creating a sleep-friendly environment can help improve sleep quality. This might include limiting caffeine, avoiding screen time before bed, and keeping your bedroom cool to combat hot flashes.

4. Support Systems: Connecting with others who are going through perimenopause, whether through support groups or online communities, can help reduce feelings of isolation and provide emotional support.

Conclusion

Perimenopause is a transitional phase that brings a lot of physical, emotional, and mental changes. The fluctuations in estrogen and progesterone can make every day feel unpredictable, but understanding the science behind these changes can help you navigate this time with more compassion for yourself. Remember that these changes are a natural part of life, and while they may be uncomfortable, they are temporary. With the right support and self-care strategies, you can manage the symptoms and come out on the other side feeling empowered and balanced.