Anxiety involves feelings of worry, nervousness, or unease, often manifesting in unexpected physical sensations. A frequent inquiry concerns whether this psychological state can cause a measurable drop in body temperature. This exploration will delve into the underlying biological systems to determine the physiological relationship between anxiety and subnormal temperature readings.
The Body’s Thermostat: How Temperature is Regulated
The normal core body temperature is generally maintained around 98.6°F (37°C), though this varies slightly based on time of day and activity. The body maintains this thermal balance through thermoregulation, centrally governed by the hypothalamus in the brain. Acting as the body’s thermostat, the hypothalamus integrates signals from central and peripheral temperature sensors.
Central sensors monitor the stable core temperature, while peripheral sensors in the skin monitor external changes. When the core temperature deviates, the hypothalamus triggers autonomic responses, such as shivering to generate heat or sweating and vasodilation to release it. These mechanisms ensure the body maintains a narrow temperature range.
Anxiety and the Fight-or-Flight Response
Anxiety triggers the fight-or-flight response, an automatic survival mechanism reacting to perceived threat. This involves the swift activation of the sympathetic nervous system (SNS). Activation begins when the amygdala signals the hypothalamus, initiating a cascade of physiological changes.
This process results in the rapid release of catecholamines, such as adrenaline and noradrenaline, and the longer-term release of cortisol. These stress hormones prepare the body for immediate action, increasing heart rate, blood pressure, and breathing rate. Energy is mobilized and senses are heightened to confront or escape the perceived danger.
Examining the Physiological Link to Subnormal Temperature
The stress response interacts with the body’s temperature regulation system, but typically does not cause a true, sustained drop in core temperature. When anxiety activates the sympathetic nervous system, it initiates peripheral vasoconstriction—a narrowing of blood vessels in the extremities. This action redirects blood flow away from the skin toward the large muscle groups and vital organs, preparing the body for physical exertion.
This shunting reduces heat loss from the core, acting as a heat-conserving mechanism. The immediate consequence is a noticeable drop in the temperature of the skin and extremities, making the person feel cold or “chilled.” If temperature is taken at peripheral sites like the mouth or armpit, the reading may show a transient, slight drop, often less than one degree Fahrenheit.
Studies confirm that while peripheral temperatures decrease during acute stress, the core temperature remains largely unaffected, suggesting the effect is localized. Furthermore, chronic anxiety and elevated cortisol levels may influence basal metabolic rate (BMR). However, anxiety-related changes are usually temporary and do not lead to a clinically significant drop. The sensation of coldness is often a misinterpretation of the blood flow redistribution, not a failure of the central thermostat.
When Low Temperature Requires Medical Attention
Anxiety can cause temporary coldness or a minor dip in peripheral readings, but rarely leads to dangerously low core body temperature. Hypothermia is defined as a core body temperature below 95°F (35°C) and is considered a medical emergency. Symptoms include uncontrollable shivering, slurred speech, clumsiness, confusion, and a weak pulse.
If temperature drops below this threshold, it is usually due to factors other than anxiety, such as prolonged exposure to cold weather. Other medical conditions can cause genuinely low temperature, including hypothyroidism, severe infection (sepsis), or nutritional deficiencies. A consistently low temperature accompanied by confusion or extreme fatigue requires immediate professional medical evaluation.