Cannot Live Without Coffee or Alcohol? Your Thirst Is a Dehydration Warning Sign

The concept of body fluids in the Donguibogam corresponds closely to fluid balance in modern medicine. Caffeine and alcohol can disrupt the body's delicate fluid-regulation system and trigger a state of chronic dehydration. First, consider caffeine. Caffeine blocks adenosine receptors in the brain to produce arousal, but at the same time, it alters kidney function to promote diuresis. It increases kidney blood flow volume, raises urine production, and mildly suppresses the secretion of antidiuretic hormone (vasopressin), thereby increasing water excretion. Along with water, vital electrolytes such as sodium, potassium, and magnesium leave through the urine, potentially causing electrolyte imbalance. Beyond simply losing water, the balance of electrolytes in the body becomes disrupted. The brain responds sensitively to these shifts, producing headache, impaired concentration, and fatigue, and in severe cases, even anxiety or restlessness. Next is alcohol. Alcohol suppresses the secretion of antidiuretic hormone much more strongly than caffeine. Antidiuretic hormone helps the kidneys concentrate urine to preserve water in the body, but when alcohol inhibits it, the kidneys cannot reabsorb water and excrete large volumes of dilute urine instead. This is why you feel severe thirst and visit the bathroom frequently the day after drinking. Chronic alcohol intake maintains this hormone suppression, leaving the brain in a state of chronic dehydration. When the water content of brain cells drops, brain volume temporarily shrinks, which can cause cognitive decline or memory impairment, as well as chronic headache or dizziness. In addition, dehydration stimulates the secretion of stress hormones like cortisol, worsening fatigue and placing a burden on the stress response system over time. Excessive intake of caffeine and alcohol upsets the body's delicate water and electrolyte balance, creating chronic dehydration that can lead to brain hypofunction, hormonal imbalance, and chronic fatigue. Drinking water only when you feel thirsty is not enough. Mindful habits are necessary to prevent body fluids from continually draining away.