Why am I so tired? The top causes of fatigue during perimenopause & menopause

If you’re constantly exhausted despite getting enough sleep, you’re not alone. Fatigue is one of the most common symptoms experienced during perimenopause and menopause, affecting up to half of women during the menopause transition. While many assume it’s simply part of ageing, hormonal changes often play a significant role.

Common causes of fatigue

One of the biggest contributors is fluctuating and declining oestrogen. Oestrogen influences energy production, brain function, muscle health and metabolism. As levels decline, many women experience reduced stamina, brain fog and lower motivation.

Sleep disturbances are another major factor. Hot flushes, night sweats, anxiety and early morning waking can significantly impact sleep quality, leaving women feeling exhausted during the day. Even mild sleep deprivation can affect energy, mood and concentration. In fact, research indicates that going 17-19 hours without sleep is the equivalent of a blood alcohol concentration of 0.05% with associated cognitive and motor performance impairments.

Metabolic changes also occur during menopause. Reduced insulin sensitivity can make it harder for the body to use glucose efficiently, contributing to energy crashes, sugar cravings and increased abdominal weight gain. At the same time, women naturally lose muscle mass during midlife, reducing metabolic efficiency and physical resilience.

Psychological factors shouldn’t be overlooked. Increased stress, anxiety and mood changes are common during the menopause transition and can contribute to feeling “wired but tired.” Chronic stress may also elevate cortisol levels, further disrupting sleep and energy production.

Additionally, conditions such as iron deficiency, thyroid dysfunction, low vitamin B12 and vitamin D deficiency can mimic or worsen menopausal fatigue.

You don’t have to put up with fatigue

The good news is that fatigue is not something women simply have to accept. Prioritising sleep, undertaking resistance training, consuming adequate protein, managing blood sugar levels, addressing stress and investigating potential nutrient deficiencies can significantly improve energy and wellbeing.

If fatigue is affecting your quality of life, consider working with me to help identify the underlying causes and develop a personalised plan. Understanding why you’re tired is often the first step towards reclaiming your energy and thriving through menopause.

References

Avis NE, Crawford SL, Greendale G, et al. Duration of menopausal vasomotor symptoms over the menopause transition. JAMA Internal Medicine. 2015;175(4):531-539.

Mauvais-Jarvis F, Clegg DJ, Hevener AL. The role of estrogens in control of energy balance and glucose homeostasis. Endocrine Reviews. 2013;34(3):309-338.

Santoro N, Epperson CN, Mathews SB. Menopausal symptoms and their management. Endocrinology and Metabolism Clinics of North America. 2015;44(3):497-515.

Maki PM, Kornstein SG, Joffe H, et al. Guidelines for the evaluation and treatment of perimenopausal depression. Menopause. 2018;25(10):1069-1085.

Ko SH, Kim HS. Menopause-associated lipid metabolic disorders and cardiovascular disease. Journal of Menopausal Medicine. 2020;26(2):83-93.