Climacteric chronic fatigue is far too complex a bodily signal to simply dismiss as a routine sign of aging. Modern medicine interprets this phenomenon as the result of hormonal imbalance and the systemic changes that accompany it.
The foremost cause is the steep decline in estrogen, a key female sex hormone. Estrogen does not merely affect reproductive organs; it is broadly involved in brain function, cardiovascular health, bone health, and energy metabolism. When estrogen levels drop, the balance of neurotransmitters in the brain is easily disrupted. By altering the secretion of serotonin, which regulates mood and sleep, and dopamine, which supports motivation and vigor, it leads to diverse fatigue symptoms such as lethargy, depressive feelings, impaired concentration, and sleep disorders.
Furthermore, dysfunction of the hypothalamic-pituitary-adrenal axis, which regulates the stress response, also worsens chronic fatigue. During the climacteric, the body is already placed in a stressed state due to hormonal shifts. When external stressors are added, the HPA axis can become hyperactivated or exhausted. As cortisol secretion patterns become disrupted, the sleep-wake cycle breaks down, causing daytime drowsiness and nighttime arousal, which can entrench chronic fatigue.
At the cellular level, mitochondrial dysfunction is identified as a core factor. Mitochondria serve as the cellular powerhouses of our body, producing energy, and estrogen exerts an important influence on mitochondrial health and efficient energy production. When estrogen drops, mitochondrial function declines and cells can no longer produce adequate energy, manifesting as systemic loss of vitality and lethargy. Much like a smartphone with reduced battery efficiency, energy drains rapidly even with ordinary use.
An increased inflammatory response is also deeply connected to chronic fatigue. During the climacteric, overall inflammatory markers tend to rise, and chronic inflammation continuously drains energy while sustaining fatigue. Psychological factors such as inadequate sleep, anxiety, and low mood further compound this cycle. Therefore, climacteric chronic fatigue should not be regarded as a single isolated symptom, but understood as a signal that the overall balance across hormones, the nervous system, cellular energy metabolism, and the immune system has been disrupted, calling for comprehensive care.
