Why Am I So Tired? Understanding Fatigue in Perimenopause
By late winter, many women feel worn down. The days are short, energy is thin, and the constant pull between work, family, and caregiving intensifies the sense of depletion. For women in their forties and early fifties, that exhaustion can feel even heavier. Perimenopause adds a physiologic layer that is often overlooked, which is why so many women are told that their fatigue is "normal," even when it is affecting their daily life.
In my practice, I see women every week who know something has shifted but have struggled to find clear answers. Fatigue is one of the most common reasons they come in. Understanding what is typical in perimenopause, and what signals something more, can offer both clarity and relief.
Why Fatigue Increases in Perimenopause
Perimenopause is marked by variability. Hormonal fluctuations do not follow a predictable pattern, and this instability influences energy regulation in several ways.
Sleep fragmentation
As estrogen levels fluctuate, sleep becomes lighter and more interrupted. Many women describe waking multiple times a night without knowing why. Others notice new onset night sweats or early morning awakenings. Even when total sleep time looks adequate, the loss of deep, restorative stages accumulates. Over time, this creates a level of fatigue that feels disproportionate to the demands of the day.
Metabolic shifts
Midlife is a period of increased insulin resistance, changes in body composition, and shifts in appetite signaling. These metabolic changes can lower daytime energy and make the body work harder to maintain equilibrium. For some women, this shows up as afternoon crashes. For others, it feels like a constant heaviness that sleep does not fix.
Mood and cognitive changes
Irritability, difficulty focusing, and emotional reactivity are common in perimenopause. These symptoms reflect real shifts in neurotransmitter activity that influence how energized or depleted you feel. Mental fatigue and physical fatigue often travel together.
Taken together, these factors explain why a woman who has always had steady energy may suddenly feel drained even in the absence of illness. This is physiologic, but it should not be dismissed.
When Fatigue Suggests Something More
Not all fatigue in perimenopause is hormonal. These red flags deserve a thorough evaluation.
Fatigue that worsens despite adequate sleep: If you are sleeping seven to eight hours yet still wake unrefreshed, it can signal conditions such as sleep apnea, thyroid dysfunction, or iron deficiency.
Shortness of breath, rapid heart rate, or exercise intolerance: These may indicate anemia or cardiovascular concerns. Women of South Asian, African American, and Hispanic descent face unique cardiometabolic risks during this transition and may benefit from earlier or more comprehensive screening.
New or progressive weakness: This is not typical of perimenopause and warrants a medical evaluation for neurologic or metabolic causes.
Unintentional weight changes: Significant gain or loss should prompt screening for thyroid disease, diabetes, or adrenal concerns.
Fatigue accompanied by heavy or prolonged bleeding: This increases the risk of iron deficiency. Many women assume they are "just tired" when their iron stores are far below optimal levels. Heavy menstrual bleeding is more common in some populations, including Black women, making iron screening particularly important.
If any of these symptoms exist, it is reasonable to look beyond hormones alone.
A Thoughtful, Evidence-Based Evaluation Plan
Fatigue deserves a structured and respectful approach. A comprehensive evaluation typically includes:
A detailed clinical history: Patterns of sleep, stress, menstrual changes, and daily energy provide essential clues. Listening is central to this process. Many women have never been asked to describe their fatigue in depth.
Hormonal assessment when indicated: While perimenopause is defined by fluctuation rather than deficiency, targeted testing can help clarify the overall picture. This supports precision without overtesting.
Thyroid evaluation: Thyroid function often shifts in midlife, and both hypothyroidism and subtle variations can amplify fatigue. A complete thyroid panel is more informative than a single value.
Iron studies and complete blood count: Iron deficiency is common in women with heavy or unpredictable cycles. It can cause pronounced fatigue even before anemia develops.
Screening for metabolic contributors: This may include glucose patterns, insulin resistance, and cholesterol changes. Metabolic shifts influence both energy levels and long-term health.
Sleep evaluation: Identifying sleep fragmentation is essential. Sometimes this means reviewing sleep hygiene and nighttime symptoms. Other times, a formal sleep study is appropriate.
The goal is not to label fatigue as inevitable. It is to identify what your body is actually asking for and to address it with clarity and respect.
What You Can Do Now
While a thorough medical evaluation helps identify underlying causes, several evidence-based strategies can support your energy in the meantime:
Prioritize sleep consistency: Going to bed and waking at the same time—even on weekends—helps regulate your circadian rhythm. Keep your bedroom cool (around 65-68°F) to counter night sweats and support deeper sleep.
Prioritize strength training alongside movement: Resistance training 2-3 times per week helps preserve bone density and muscle mass, both of which decline during perimenopause. This supports metabolism, weight management, and reduces fracture risk long-term. Pair this with daily walks or other moderate activity, consistency matters more than intensity. Excessive high-intensity workouts can worsen fatigue, so listen to your body's recovery signals.
Support stable blood sugar: Eating protein and fiber at each meal helps prevent the energy crashes that come from blood sugar swings. This is especially important as insulin resistance increases in midlife.
Consider your iron intake: If you have heavy periods, focus on iron-rich foods like lean meat, beans, and dark leafy greens. Vitamin C helps absorption pair these foods with citrus, tomatoes, or peppers.
Limit evening alcohol and caffeine: Both interfere with sleep architecture, reducing the restorative deep sleep that's already compromised in perimenopause.
These steps will not resolve every cause of fatigue, but they create a foundation that supports your body during this transition.
Moving Forward with Support
If you are navigating perimenopause and feel more tired than you ever have, you are not imagining it. Fatigue is common in this life stage, but it is not something you must accept without understanding. There are clear physiologic reasons you may feel depleted, and there are also treatable conditions that should not be overlooked.
Medical care begins with listening. Together with your healthcare provider, you can sort through the overlapping causes of fatigue and create a plan that helps you feel steady and well again. If your current provider has dismissed your symptoms or suggested you simply need to accept them, seeking a second opinion from someone who specializes in this life stage can make all the difference.
If you are ready to explore what is driving your symptoms, I welcome you to reach out and learn more about how we can support you through this transition.
