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Carbon Dioxide Springs: "The Bubble Waters" for Gentle Circulation

Published May 5, 2026·1min read

Carbon dioxide springs contain CO₂ at 1,000 mg/kg or more — bubbles adhere to skin on bathing, earning the nickname "the bubble waters." CO₂ absorbed through skin dilates capillaries, warming the body even in lukewarm water (35–38°C) with minimal cardiac strain.

Carbon Dioxide Springs: "The Bubble Waters" for Gentle Circulation
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Table of Contents
  1. What is a Carbon Dioxide Spring?
  2. Indications for Bathing
  3. Indications for Drinking
  4. How to Bathe in a Carbon Dioxide Spring

What is a Carbon Dioxide Spring?

A carbon dioxide spring contains free carbon dioxide (CO₂) at 1,000 mg per kilogram of spring water or more. These springs are rare in Japan but notable examples exist in Nagano and Oita prefectures.

When you bathe, tiny CO₂ bubbles cling to your skin — nicknamed "the bubble waters" or "ramune waters." The CO₂ absorbed through the skin dilates peripheral capillaries, so even lukewarm water (35–38°C) warms the body effectively with less burden on the heart than hot springs.

Indications for Bathing

  • Cuts
  • Peripheral circulatory failure
  • Excessive sensitivity to cold
  • Autonomic instability

Indications for Drinking

  • Gastrointestinal hypofunction

How to Bathe in a Carbon Dioxide Spring

  1. CO₂ escapes at high temperatures — soak in a lukewarm source (35–38°C) for longer, do not stir the water.
  2. Gently lower yourself into the water; agitation disperses the bubbles.
  3. Well-suited for the elderly and those with heart conditions — stay hydrated.
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