硫酸塩泉

Sulfate is the dominant anion. The three historic sub-names are still seen on signage: 芒硝泉 (sodium), 石膏泉 (calcium), 正苦味泉 (magnesium). Traditionally valued as 傷の湯 — "water for wounds" — and generally sedative.

What it is like

Clear, faintly bitter. Calcium examples often leave a chalky white crust around the spout — a good visual tell.

Indications (適応症)

Cuts, poor peripheral circulation, sensitivity to cold, low mood, dry skin. Where drinking is permitted: biliary complaints, chronic constipation.

Contraindications (禁忌症)

Can act as a laxative when drunk; observe the posted quantity.

適応症 and 禁忌症 are the claims a certificate is permitted to state under the Hot Spring Act. They are not medical advice, and nothing here is. If you have a heart condition, are pregnant, or are unwell, ask a doctor rather than a guidebook.