What Are Contraindications for Onsen? | Conditions & Diseases That Prohibit Bathing

Types of Contraindications

General Contraindications (All Spring Types)

• Acute illness (especially with fever)The heat from bathing can place additional stress on the body and may worsen symptoms when you are already ill. Soaking in hot water with a fever can interfere with the body's natural ability to regulate temperature, potentially prolonging recovery.
• Active tuberculosisThis is a serious infectious disease, and the physical stress from hot water bathing can be detrimental to recovery. It is crucial to follow a physician's guidance and complete treatment before considering onsen use.
• Malignant tumorsThe increased body temperature and circulation from hot bathing may place undue stress on the body. As a general precaution, individuals undergoing treatment or with active malignant tumors should avoid onsen until cleared by a physician.
• Serious heart disease or severe arteriosclerosisThe heat from the onsen causes blood vessels to dilate, which can lead to sudden drops in blood pressure. This places significant strain on the cardiovascular system and can be dangerous for individuals with serious heart conditions or advanced arteriosclerosis.
• Respiratory or renal failureThe combination of heat, humidity, and water pressure can strain the respiratory and circulatory systems. This may make breathing more difficult for those with lung conditions or disrupt fluid and blood pressure regulation in individuals with kidney failure.
• Hemorrhagic disordersHot water increases blood flow and dilates blood vessels, which can interfere with the body's ability to form clots. This poses a risk for individuals with disorders that affect bleeding or those who are prone to hemorrhaging.
• Severe anemiaThe drop in blood pressure often caused by hot water immersion can lead to dizziness or fainting. This risk is significantly heightened in individuals with severe anemia due to the blood's reduced oxygen-carrying capacity.
• Pregnancy (especially first and third trimesters)Raising the core body temperature during the first trimester can pose risks to fetal development. In later stages, the risk of dizziness, fainting from blood pressure changes, and potential slips increases, making it a general precaution to avoid onsen.

Spring-Specific Contraindications (Examples)

• Acidic springs: sensitive skin/mucous membranes, eye diseasesThe high acidity of these springs can be strongly stimulating, which may cause irritation for those with sensitive skin or mucous membranes. Bathers should also avoid getting the water in their eyes, as it can be particularly aggravating for those with existing eye diseases.
• Sulfur springs: severe cases of chronic dermatitisWhile often associated with skin benefits, the potent nature of sulfur springs can be too harsh for severely compromised skin. Individuals with severe cases of chronic dermatitis may experience adverse reactions or a worsening of their condition, making it a specific contraindication.
• Radioactive springs: during radiation therapy, pregnancyBathing is not recommended for individuals undergoing medical radiation therapy to avoid any cumulative effects from exposure. As a general precaution, it is also advised to avoid these springs during pregnancy, particularly in the early and late stages.
• Iodine springs: those with thyroid conditions should confirm with a doctorIodine can be absorbed through the skin and may influence thyroid function. For individuals with pre-existing thyroid conditions, this external intake could interfere with their treatment or health status, so consulting a physician beforehand is essential.