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Senjonoyu Hot Spring

Water profile

Senjonoyu Hot Spring

Spring chemistry and what it does, with the research behind it.

Simple

A gentle simple thermal spring — hot at 45.6 °C, with neutral pH and hypotonic mineralization, served as free-flow source water (kakenagashi). With little chemical bite, it relies on heat and water volume rather than mineral punch, and the posted indications list the usual constellation of nerve pain, muscle ache, joint stiffness, and post-illness recovery.

Good for

Aches & joints

Warmth eases stiffness and raises the pain threshold. Radon and sulfate springs show the strongest evidence for joint and muscle pain.

stiff shoulders

On the certificate:神経痛Muscle painJoint painFrozen shoulderMotor paralysisJoint stiffness打ち身Sprains

Recovery

Warmth and buoyancy lower stress markers and improve sleep; habitual bathing is linked to lower rates of depression.

fatigue, stress

On the certificate:ConvalescenceFatigue recoveryGeneral health improvement

Take care

Contraindications
  • 急性疾患(特に熱のある場合)
  • Active tuberculosis
  • Malignant tumor
  • 重い心臓病
  • 呼吸不全
  • Renal failure
  • Bleeding disorders
  • Severe anemia
  • その他一般に病性進行中の疾患
  • 妊娠中(特に初期と末期)

Measured at the source

Source temperature
45.6°C
Hot
Tonicity
Hypotonic

On the certificate

  • Chronic digestive disorders
  • Hemorrhoids
  • Cold sensitivity

Evidence

  1. Maeda M. 温泉の医学的効果とその科学的根拠. J. Hot Spring Science 70:197–207, 2021.
  2. Donaubauer AJ et al. Serial radon spa therapy on pain in musculoskeletal disorders. Frontiers in Immunology, 2024.
  3. Verhagen AP et al. Balneotherapy for rheumatoid arthritis. Cochrane Database of Systematic Reviews CD000518, 2015.
  4. Takeda M et al. Hot spring bathing practices have a positive effect on mental health in Japan. Heliyon 9(9):e19631, 2023.

Educational, not medical advice. If you have a health condition, consult a physician before onsen therapy.