湯Simple
A simple thermal spring — gentle, lightly mineralized water without the sharpness of an acidic or strongly salty source, which makes it easy to settle into for a long soak. The posted panel names the spring-type-specific indications for this water as autonomic nervous system instability, insomnia, and depressed mood, placing it with the calming sources rather than the therapeutic heavy-hitters, and it records no spring-type-specific contraindications at all.
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:Muscle stiffness associated with motor paralysis
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 improvementAutonomic nervous system instabilityInsomniaDepressed mood
Take care
Contraindications
- Active stage of any illness (especially with fever)
- Active tuberculosis
- Advanced malignant tumor, severe anemia, or other marked physical debilitation
- Severe heart or lung disease causing breathlessness on slight exertion
- Severe kidney disease with edema
- Gastrointestinal bleeding
- Visible bleeding
- Acute exacerbation of a chronic illness
Measured at the source
Source temperature
53.5°C
Hot
On the certificate
- Chronic muscle or joint pain and stiffness (rheumatoid arthritis, osteoarthritis, lower back pain, neuralgia, frozen shoulder, bruises, sprains — chronic phase)
- Cold sensitivity
- Peripheral circulation disorders
- Reduced gastrointestinal function (heaviness, bloating)
- Mild hypertension
- Impaired glucose tolerance (diabetes)
- Mild hypercholesterolemia
- Mild asthma or emphysema
- Hemorrhoid pain
- Stress-related symptoms (sleep disorders, depressed mood)
Evidence
- 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.
- Donaubauer AJ et al. Serial radon spa therapy on pain in musculoskeletal disorders. Frontiers in Immunology, 2024.
- Verhagen AP et al. Balneotherapy for rheumatoid arthritis. Cochrane Database of Systematic Reviews CD000518, 2015.
- Takeda M et al. Hot spring bathing practices have a positive effect on mental health in Japan. Heliyon 9(9):e19631, 2023.