Exhaustion

Noradrenaline

Exhaustion and rapid fatigue can be closely linked to noradrenaline (norepinephrine)—a key neurotransmitter involved in energy, alertness, and the body’s stress response. Noradrenaline helps mobilize the brain and body for action, particularly during times of stress or demand. When levels are low or dysregulated, you may feel persistently tired, unmotivated, mentally sluggish, and unable to bounce back after physical or mental exertion. This can result from chronic stress, adrenal fatigue, poor sleep, nutrient deficiencies (especially vitamin C, B6, and copper), or imbalances in your autonomic nervous system.

Feeling constantly tired—even after rest—isn’t just about sleep or workload. Chronic exhaustion and rapid fatiguing are often driven by deep-rooted hormonal imbalances, especially when stress has been prolonged. The body’s internal chemistry plays a vital role in energy production, recovery, and endurance.

Adrenaline (Epinephrine)

Adrenaline provides a short-term energy boost during stress. It prepares the body for immediate action by increasing heart rate and mobilizing energy. In chronic stress, adrenaline is overused. Eventually, the adrenal glands struggle to produce enough, leading to energy crashes, sluggishness, and fatigue, even with minimal activity. The body becomes less responsive to natural stimulants, making basic tasks feel draining.

GABA (Gamma-aminobutyric acid)

GABA helps the brain calm down and recharge. It balances excitatory signals and promotes deep rest, both physically and mentally. When GABA is low, the nervous system stays overstimulated, preventing true relaxation or recovery. This leads to restless sleep, poor focus, and faster physical and mental exhaustion during the day—even after a full night’s rest.

DHEA (Dehydroepiandrosterone)

DHEA supports cellular energy, muscle function, and stamina. It also helps counteract the catabolic effects of stress on the body. Low DHEA levels result in reduced endurance, loss of muscle strength, and slower recovery from both physical and emotional exertion. It’s especially important in preventing midday crashes and burnout-related fatigue.

Cortisol

Cortisol manages the body’s long-term energy and stress response. It regulates blood sugar, inflammation, and daily energy cycles. Cortisol dysregulation (either too high or too low) disrupts your body’s natural rhythm.

High cortisol causes wired-but-tired states and poor-quality sleep

Low cortisol causes persistent fatigue, even after minimal effort Over time, this creates a cycle of exhaustion that rest alone can’t fix.

Glutamate

Glutamate is a stimulating neurotransmitter, essential for cognitive function and alertness—but when it's out of balance, it can contribute to mental and physical exhaustion.

How It Works:

Under chronic stress or inflammation, glutamate levels can build up in the brain, especially if glial cells can’t clear it efficiently.

This overactivation of neurons leads to a state of constant neural firing, draining brain energy stores and overloading the nervous system.

Over time, this results in:

• Mental burnout

• Low resilience to stressors

• Rapid cognitive and physical fatigue even after minimal effort

Areas like the prefrontal cortex and hippocampus—key for focus, decision-making, and motivation—are especially vulnerable to glutamate-related fatigue.

Fast Fatigue? Here’s Why:

When neurons are overstimulated, they require more ATP (cellular energy) to recover.

This increased energy demand leads to:

• Quicker depletion of energy reserves

• Slower recovery between tasks

• Perception of “crashing” or hitting a wall quickly

This contributes to rapid fatiguing, even with basic tasks like reading, thinking, or walking.