A panic attack is defined as a sudden, intense surge of fear and discomfort that reaches a peak within minutes. This intense physiological event activates the body’s energy systems in a dramatic, short-lived response. Since any bodily function requires energy, panic attacks do consume calories. However, the total number of calories burned is minimal and holds no significance for metabolic health or weight management. The physical symptoms are driven by a massive internal energy redirection, not a sustained caloric expenditure comparable to physical exercise.
The Physiology of Calorie Consumption During a Panic Attack
The temporary increase in energy expenditure is caused by the activation of the sympathetic nervous system, known as the “fight-or-flight” response. This cascade begins when the brain signals the adrenal glands to release a flood of hormones, primarily adrenaline (epinephrine) and cortisol. Adrenaline acts rapidly, preparing the body for immediate action against a perceived threat.
This hormonal surge causes the heart rate to accelerate dramatically (tachycardia), demanding more energy from the cardiac muscle. Breathing becomes shallow and rapid (hyperventilation) to increase oxygen intake, further consuming calories through increased respiratory muscle work. Cortisol simultaneously stimulates the liver to release stored glucose and fats into the bloodstream, providing readily available fuel for the body’s major muscle groups.
Muscles throughout the body tense up in preparation, which may manifest as trembling or shaking, requiring a continuous supply of energy. The body redirects blood flow away from non-essential systems, like the digestive tract, toward the muscles and the brain. This widespread physiological mobilization temporarily elevates the body’s metabolic rate above its resting state.
Quantifying the Caloric Expenditure
While a panic attack feels physically exhausting, the actual caloric expenditure is quite low because the event is typically short-lived, often peaking and subsiding within 10 to 30 minutes. For a standard 10-minute panic attack, the additional energy burned beyond the body’s normal resting rate is estimated to be approximately 10 to 30 calories. This figure represents the energy cost of the accelerated heart rate, rapid breathing, and muscle tension.
To put this into perspective, the energy spent is similar to or slightly more than the calories an average person burns simply by sitting quietly for the same length of time. Walking slowly for 10 minutes burns roughly 30 to 40 calories, while a brisk 10-minute walk could consume 50 to 80 calories. The metabolic spike from a panic attack does not contribute meaningfully to overall energy balance or weight loss efforts.
The intensity of the internal experience does not translate into a significant external energy output like exercise. Even during severe episodes involving intense shaking and hyperventilation, the caloric burn remains modest and cannot be sustained long enough to rival even light physical activity. The primary metabolic effect is the rapid mobilization of fuel sources, not the burning of a large total amount of stored energy.
The Metabolic Aftermath
As the acute threat passes and the body begins to recover, the metabolic consequences become more noticeable than the acute burn. The sudden rush of adrenaline subsides, but the body must now expend energy to return to a state of homeostasis, or balance. This recovery period is why many people experience profound physical and mental exhaustion immediately following an attack.
The body’s immediate reserves of readily available glucose, which were mobilized by cortisol and adrenaline, become depleted during the acute phase. The fatigue experienced, often referred to as a “panic attack hangover,” stems from this rapid depletion and the subsequent effort required to replenish these energy stores. This process of re-regulating blood sugar and hormone levels demands sustained metabolic activity.
Furthermore, stress hormones like cortisol can linger in the system for a time after the attack has peaked. While cortisol helped mobilize glucose, its continued presence can influence short-term appetite regulation and blood sugar stability as the body attempts to normalize. The overall metabolic stress of the event, including the need for system-wide recovery and hormone clearance, is a distinct energy cost separate from the small, acute calorie burn.