The sensation of feeling a sudden chill or shivering after consuming alcohol is a common physiological reaction. This feeling, often described as having the “chills,” is a sign that the body’s internal systems are reacting to the presence of ethanol. The feeling of being cold or shaky results from several biological processes that alcohol disrupts, affecting temperature regulation and metabolic balance. Understanding these mechanisms reveals that the chills are a warning sign from the body’s defense and compensation systems.
How Alcohol Disrupts Your Body’s Thermostat
Alcohol is a potent vasodilator, causing blood vessels near the skin’s surface to widen and relax. This dramatically increases blood flow to the extremities, creating a deceptive, temporary feeling of warmth. While this rush of warm blood makes a person feel flushed, the increased surface blood flow accelerates the rate at which heat is lost to the environment.
The body’s core temperature begins to drop as heat rapidly radiates away from the skin. This effect makes alcohol consumption a significant risk factor for hypothermia, a condition where the core body temperature falls below 95°F (35°C). The central nervous system, which acts as the body’s thermostat, detects this decrease. The brain responds by initiating a compensatory mechanism: shivering.
Shivering involves rapid, involuntary muscle contractions designed to generate heat through movement. This process attempts to counteract the heat loss caused by vasodilation. Alcohol also impairs the thermoregulatory center in the brain, lowering the threshold for heat conservation. This impairment makes the body less effective at regulating its temperature.
The Connection Between Alcohol and Blood Sugar Drops
Another significant cause of chills and shakiness is alcohol’s effect on maintaining stable blood sugar levels. A drop in blood glucose, known as hypoglycemia, can trigger symptoms that mimic the chills. This occurs because the liver, which detoxifies alcohol and regulates glucose, prioritizes metabolizing the alcohol.
The liver normally maintains blood sugar by releasing stored glucose through gluconeogenesis. When alcohol is present, the liver shifts its resources to break down ethanol, sidelining the glucose production pathway. This suppression of glucose release causes blood sugar levels to fall, especially if drinking occurs on an empty stomach or for an extended period.
Low blood sugar deprives the brain and muscles of their primary energy source, leading to weakness, fatigue, and shakiness. The body’s response to this energy crisis involves releasing stress hormones. These hormones can cause internal tremors and a cold, clammy feeling often confused with temperature-related chills.
Dehydration and the Circulatory System
Alcohol acts as a diuretic, causing the kidneys to increase urine production and resulting in a net loss of fluid. This excessive fluid loss quickly leads to dehydration, which reduces the overall volume of fluid in the bloodstream.
A decrease in blood volume strains the circulatory system, forcing it to work harder to deliver nutrients. The body compensates by slightly constricting blood vessels in certain areas to maintain blood pressure, contributing to a cold or clammy feeling. Furthermore, the inflammatory response triggered by alcohol releases immune chemicals called cytokines, which can contribute to flu-like symptoms and general malaise.
Warning Signs and When to Seek Help
While mild chills are often a consequence of the body adjusting to alcohol, they can also signal a serious, life-threatening emergency, such as severe intoxication or poisoning. It is important to recognize the difference between a common reaction and a medical crisis. Chills accompanied by signs of severe hypothermia, such as a low body temperature and pale or bluish skin, require immediate attention.
Immediate medical attention is required if the person is confused, incoherent, or cannot be easily roused. Severe warning signs include slow or irregular breathing, defined as fewer than eight breaths per minute or pauses lasting more than ten seconds.
If a person is experiencing seizures, continuous vomiting, or has clammy skin, these are clear indicators that the body is overwhelmed and emergency services must be contacted immediately. Never leave an intoxicated person alone, as symptoms can progress rapidly and lead to loss of consciousness or choking.