Hot Spring Therapy for Mild Hypertension | All 10 Types & the Special Role of CO₂ Springs

The Oyado Yuraku Gensen is a private source bubbling up in the central area of Yufuin Onsen, a town known for its idyllic rural landscapes at the foot of Mt. Yufu. Many of Yufuin's springs, a long-cherished health resort area, are classified as simple hot springs gentle on the skin. This source is one of them, characterized by its mild and soft touch. Immersing yourself in its waters feels like being embraced by the serene nature of Yufuin, offering a peaceful respite for resetting mind and body away from daily life.

This hidden gem springs forth in Akiruno, a city in Tokyo blessed with abundant nature. Its most remarkable feature is its exceptionally high alkalinity, with a pH of 10.01, one of the highest in Japan. The water feels silky and lotion-like, and is traditionally associated with smoothing the skin. It is a gentle and soothing spring, perfect for those seeking to heal daily fatigue and refresh both mind and body.

Osawa Onsen, a famed hot spring in Iwate reportedly beloved by author Kenji Miyazawa, draws from the "Osawa-no-Yu" source. It boasts a silky, lotion-like texture, a gift of its high alkalinity at pH 9.0. Soaking in this smooth water, like a fine lotion, gently exfoliates the skin, leaving it feeling exceptionally smooth after your bath. It's a gentle, healing spring that soothes both mind and body, perfect for those seeking a peaceful escape to unwind and care for themselves.

Nestled in Kasugai-cho, Fuefuki City, Yamanashi Prefecture, a region renowned for its grape cultivation, this gentle hot spring is a true blessing from the earth, cherished by locals for generations. Its lukewarm waters, around 36.3℃, offer a comfort that invites you to linger indefinitely. The soft, weakly alkaline water delicately envelops the skin, gradually releasing tension from the body's core. It's a soothing retreat for those seeking to alleviate daily fatigue and find deep relaxation in mild waters.

Hakone Yumoto Onsen, the historic gateway to Hakone Onsenkyo, opened in the Nara period and flourished as the foremost of the 'Hakone Nanayu' (Seven Hot Springs of Hakone) during the Edo period. This particular hot spring vein, a pillar of the region's heritage, offers thick, soft waters that gently envelop the skin, promoting deep relaxation for both mind and body. After bathing, the wonderfully smooth skin feel provides a comforting embrace, inviting guests to forget daily hustle and bustle and indulge in self-care.

Once a desolate area called "Lesser Hell," this land was renamed Kowakidani following a visit by Emperor Meiji, sparking its development as a hot spring resort. This combined source is one of several springs utilized in this historic onsen town. Developed by entrepreneurs in the Meiji era, the area saw the construction of numerous inns and villas. This very source has supplied water to accommodations throughout the Kowakidani area, laying the foundation for Hakone's modern onsen culture.

This hot spring embodies the enduring passion of pioneers, delivered from Kuronagi Onsen in the upper reaches of the Kurobe River to Unazuki Onsen, approximately 7km downstream, after arduous wooden pipe laying construction in Taisho 12 (1923). Gushing at an abundant rate of approximately 2,000 liters per minute, its colorless and transparent waters seem to embody the pristine clarity of the gorge itself. With a soft touch that gently envelops the skin, it slowly warms the body to its core. Ideal for those seeking to unwind their mind and body, embraced by nature, at the various inns and public bathhouses throughout the town.

The Miyagino Combined Spring supplies the Gora Onsen area, one of Hakone's 17 famous springs. Since successful drilling around 1965, this source has supported the development of the Miyagino district as a health resort. By blending multiple sources, it maintains a stable volume and quality. The soft, weakly alkaline water is gentle on the skin, leaving it feeling smooth after bathing. It is recommended for those seeking a moment of peace to gently unwind both body and mind amidst Hakone's rich nature.

Amagase Onsen is one of Bungo's three great hot springs, alongside Beppu and Yufuin. The Ukihabekan Shinshiyo source is drawn via a 150-meter deep powered drill from a hillside site. With over 1,300 years of history, Amagase's waters were mentioned in the ancient "Bungo Fudoki" chronicles and have long been cherished for therapeutic bathing. This source combines pH 8.9 alkalinity with sulfur properties, gently removing old skin cells for a smooth feel. You can enjoy a silky skin sensation after bathing, perfect for those seeking to refresh mind and body.

Hakone-Yumoto Onsen, said to have opened in the Nara period, boasts the oldest history in Hakone. This Yumoto No. 29 & 46 Goko-sen is a blend of multiple sources from this historic spa town. It is used in public bathhouses along the old Tokaido road, having soothed weary travelers for centuries.

Gushing in the Kannawa Onsen area, one of the eight springs of Beppu, Japan's top onsen destination, the Akari no Yado Tougetsu Gensen is a relatively new source, drilled and pump-lifted for a facility that opened in 2019. It offers modern relaxation while inheriting the traditions of Kannawa, long-famed as a therapeutic spa area. With a neutral pH of 6.8, close to human skin, the water is gentle and suitable for everyone. Immersing yourself in these waters helps you forget the hustle and bustle of daily life, deeply relaxing both mind and body.

This private source is pumped from 300 meters underground in the port area of Beppu, Japan's premier onsen city. Drilled exclusively for the Hotel Sun Valley Annex, this spring delivers the blessings of Beppu's waters to its visitors. [3] The simple, mildly alkaline thermal water is gentle and characterized by a smooth texture that softly envelops the skin. After bathing, the skin feels silky and deeply moisturized. It is an ideal spring for those seeking to gently unwind both body and mind amidst the energy of Beppu.

This naturally gushing mixed source is located about 7km upstream from Unazuki Onsen, nestled within the Kurobe Gorge's Kuronagi Onsen area. Since its water was first drawn through wooden pipes in Taisho 12 (1923), it has continuously supplied a generous 2,100 liters per minute of hot spring water to the Unazuki Onsen town. Renowned as Japan's clearest, its soft waters gently embrace the skin and offer a restorative warmth that permeates deep into the body. It is highly recommended for those seeking deep relaxation, rejuvenation, and a chance to forget daily fatigue amidst the blessings of magnificent nature.

This Radon-sen No. 1 source plays a key role as one of the "Ginsen" (Silver Springs) that color the history of Arima Onsen, one of Japan's three ancient hot springs. In contrast to the reddish-brown "Kinsen" containing iron, Ginsen is characterized by its clear, smooth feel. The water from this source is said to gently stimulate cells and vitalize the body as it's absorbed through breathing.

The Poppo-an source is a private wellspring drilled in the tranquil countryside of Yufuin, one of Japan's premier onsen destinations. Located amidst serene landscapes with views of Mt. Yufu, its name is said to derive from the beloved local train that runs nearby. This alkaline simple spring is characterized by its gentle, non-irritating waters that seem to smoothly envelop the skin. After bathing, your skin will feel deeply moisturized, filling both mind and body with profound relaxation.

Gushing forth in the Yufuin Onsen area at the foot of Mt. Yufu, the Yufuin Yubel Hotel No. 1 Spring embodies the town's spirit. Yufuin, one of Japan's most famous hot spring resorts, has a history of avoiding boisterous development, instead cultivating a tranquil retreat where pastoral landscapes meet art. This alkaline simple spring, with its low-irritant properties, is a perfect expression of that philosophy. The soft, pH 8.5 water gently envelops the skin, leaving it feeling smooth and refreshed after bathing. It is a fine spring that offers a peaceful escape for those seeking to unwind both body and soul.

Kuronagi Onsen, a major source gushing from the Kuronagi River, a tributary of the Kurobe River, was discovered in 1645 by Tarozaemon of Otozawa Village. During the Edo period, it was renowned as a hidden hot spring of the Kaga Domain. Its colorless, transparent, and soft waters gently envelop the skin, warming the body to its core. After bathing, you feel surprisingly light, with a sense of rejuvenation from within. This blessed spring, whose waters are also delivered to Unazuki Onsen about 7 kilometers away, offers solace to those seeking to liberate mind and body amidst grand nature and rediscover their true self.

Nestled within the grounds of Suzuka Circuit, one of the world's premier racing courses, this unique hot spring has offered a soothing retreat to race fans and families since its 1994 opening. Its weakly alkaline waters, drawn from underground, are gentle on the skin with minimal irritation, effortlessly permeating the body. Ideal for cooling race excitement and gently refreshing an uplifted mind and body, this spring continues its legacy of healing in a renewed form since 2023, providing tranquility to all visitors.

This is one of the private sources gushing in Yufuin Onsen, one of Japan's most popular hot spring resorts. The "On-yu" source is a simple hot spring drawn from within the property, known for being gentle and suitable for everyone due to its low mineral content. Its weak alkalinity of pH 8.2 gently removes dead skin cells, leaving the skin feeling smooth. Rich in metasilicic acid, a natural moisturizing component, it helps hydrate the skin after bathing. This spring is recommended for those seeking a gentle bath to unwind both body and soul while surrounded by the majestic nature of Mount Yufu.

As its name "Asagiri no Yu" (Morning Mist Bath) suggests, this source gushes forth in a location overlooking the Yufuin Basin's magical morning mist. It is a private source nurtured by one of Yufuin's most historic establishments, founded in 1911. The alkaline simple spring is gentle on the skin. Its abundant metasilicic acid helps to wash away old skin cells, leaving your skin feeling silky smooth. It is a renowned spring perfect for days when you wish to quietly reset your mind and body at the foot of Mt. Yufu.

Pumped from 1,000 meters beneath the Kuju Highlands in Aso-Kuju National Park, the Tenku no Daichi Kuju Kogen Hotel source is a true all-star spring, combining the properties of chloride, sulfate, and bicarbonate waters. Rich in metasilicic acid, a natural moisturizer, it leaves skin feeling smooth during the bath and wonderfully soft afterward. It's perfect for days when you want to deeply soothe body and soul while gazing at the majestic nature of the Kuju mountain range and Mount Aso.

This rare, naturally gushing source emerges from beneath 'Gensenkaku,' nestled beside Kusatsu Onsen's iconic Yubatake (Kusatsu's central hot-water field). Despite its strong acidity, its waters offer a remarkably soft bathing sensation, akin to being enveloped in silk floss. The milky-white waters, renowned for having Kusatsu's finest 'yunohana' (hot spring minerals), gently embrace the skin, contributing to silky skin and providing a restorative warmth that lingers deep within the body. Known as a 'phantom spring' for its history of disappearing once during the Taisho era, it now offers a profound escape from daily life, inviting deep relaxation and rejuvenation.

The Mandaiko source, originating from traces of past mining development, is deeply intertwined with Kusatsu Onsen's unique yumomi culture and its long history of toji (therapeutic bathing). Its highly acidic waters, among Japan's most potent, deliver a distinctive tingling sensation, awakening both mind and body and offering a sense of rejuvenation. The high-temperature blessings penetrate deep into the core, leaving you with a surprisingly light and refreshed feeling after your bath. We invite those seeking a genuine toji experience, a true escape from daily life to restore their mind and body, to discover the profound power of this spring.

This is one of the most well-known sources in Noboribetsu, a leading onsen destination in Hokkaido. It continuously flows at a high temperature of 96.5°C, embodying the raw power of the earth. The highly acidic water, with a pH of 2.2, provides a tingling sensation on the skin and a refreshing feeling after bathing. Its rich iron and sulfate content offers a powerful bathing experience that feels as if it's awakening both mind and body. It's a spring for those who wish to reset from daily fatigue, gain new vitality, and feel nature's energy throughout their entire being.

This source, naturally gushing 200 liters per minute from the Toyohira River riverbed in Jozankei Onsen town, began supplying surrounding hot spring facilities in 1997, named after its founder, Jozan Miizumi. Its colorless, clear waters, with a faint hint of sulfur, are characterized by a gentle salt veil that envelops the skin. The heat slowly penetrates to the body's core, providing restorative warmth that lingers long after bathing. It is a renowned spring offering deep relaxation for those seeking to escape daily hustle and warm their mind and body.

The 'Mixed Source No. 9 and 10' naturally gushes from the riverbed of the Toyohira River, which flows through Jozankei Onsen. By blending multiple private sources, this unique and rich hot spring water is created. A gentle salt veil envelops the skin, delivering warmth deep into the body's core, and a pleasant restorative warmth lingers long after bathing. This blessing from the earth is especially recommended for those seeking to release daily fatigue and experience deep relaxation.

This is a newly drilled source in the Yufuin Onsen area, which boasts one of the largest outputs in Japan. Nestled at the foot of Mt. Yufu, this hot spring resort has long been cherished for therapeutic bathing. The AMBER Yufuin source features a high alkalinity of pH 8.9, combining the qualities of a bicarbonate spring that smooths the skin by removing old keratin, and a chloride spring that helps retain body heat. It is particularly characterized by its abundance of metasilicic acid, a natural moisturizing component.

This rare, naturally gushing source emerges from beneath 'Gensenkaku,' nestled beside Kusatsu Onsen's iconic Yubatake (Kusatsu's central hot-water field). Despite its strong acidity, its waters offer a remarkably soft bathing sensation, akin to being enveloped in silk floss. The milky-white waters, renowned for having Kusatsu's finest 'yunohana' (hot spring minerals), gently embrace the skin, contributing to silky skin and providing a restorative warmth that lingers deep within the body. Known as a 'phantom spring' for its history of disappearing once during the Taisho era, it now offers a profound escape from daily life, inviting deep relaxation and rejuvenation.

The Bandaiko source, which unexpectedly erupted from within the Bandai Sulfur Mine in 1970, now stands as Kusatsu's primary hot spring, boasting the largest output and supporting the town. Named with the wish for 'eternal prosperity' (万代), this powerful source was born in the mountains, far from the Yubatake (Kusatsu's central hot-water field). Its colorless, transparent waters deliver a stimulating tingle that awakens both mind and body, while its robust warmth permeates to the very core. This energetic spring is a perfect companion for those seeking liberation from daily routines and a crisp mental and physical rejuvenation.

The New Heartopia Onsen, located in Nagashima-cho, Kuwana City, Mie Prefecture, an area famous for Nagashima Resort, is sourced from deep underground through drilling and pump-lifting. Its soft, saline waters create a delicate veil on the skin, gently warming the body from its core. The restorative warmth lingers long after bathing, offering deep relaxation for both mind and body. This spring provides a soothing embrace for those seeking profound tranquility after a day of enjoyment in this vibrant leisure destination.

The Kowakien Kyokyu Onsen is a steam-generated spring developed since 1949 to supply the Hakone Kowakien resort area. It utilizes geothermal heat from former fumarolic activity along the Kurumazawa stream, a tributary of the Jakotsu River, blending multiple sources and natural spring water. This source is widely distributed to the various facilities of the Hakone Kowakien resort, operated by Fujita Kanko, forming the foundation of the entire resort.

Hirayu Onsen, nestled deep within Okuhida Onsenkyo and embraced by the Hida Mountains, is an ancient hot spring said to have been discovered by Takeda Shingen's defeated warriors. Its waters, rich in chloride and bicarbonate springs, gently refine the skin, promoting a silky skin sensation, while delivering restorative warmth deep into the body. This pleasant warmth lingers long after your bath, feeling like a blessing from the mountains. It is highly recommended for those seeking deep relaxation and a respite from daily life while admiring the Northern Alps, or for hikers wishing to soothe their weary bodies.

Discovered in 1992, Kumihama Onsen, drilled from 1500m underground, emerges in the scenic Kumihama Bay area of northern Kyoto Prefecture, facing the Sea of Japan. Its colorless, transparent, and mild waters are renowned for a gentle, skin-enveloping veil of salt. This unique quality delivers restorative warmth deep into the body's core, ensuring a lasting sense of comfort long after you leave the bath. It's an ideal retreat for those seeking deep relaxation and a profound escape from daily life amidst stunning rias coastlines.

Gora Onsen is a unique "steam-created spring," established in the early Showa period, born from the reaction between volcanic steam from Owakudani and water from Sengokuhara. This blessing embodies the fusion of Hakone's natural power and human ingenuity. A gentle salt veil envelops the skin, delivering heat deep into the body's core, ensuring restorative warmth that lingers long after your bath. It's the perfect spring to soothe the fatigue of an active day and quietly replenish your vitality for tomorrow.

This private source gushes in the Kitahama district, part of Japan's premier onsen resort, Beppu, overlooking the bay. Located in an area that has long flourished as an entertainment district, this spring has soothed countless travelers. Combining the qualities of a bicarbonate and a chloride spring, its waters gently exfoliate the skin while a veil of salt locks in moisture. After bathing, you can enjoy a unique texture that is both silky and deeply hydrated. It is a renowned spring perfect for releasing mind and body while feeling the Beppu sea breeze.

The Niseko-cho source is pump-lifted from the base of Niseko Annupuri International Ski Resort. Developed by the Hokkaido Chuo Bus Group, its colorless, clear waters are widely supplied to nearby hot spring facilities. Drawn from abundant natural forests, this spring offers a soft touch and provides restorative warmth, gently heating the body to its core. A subtle salt veil envelops the skin, leaving a lasting warmth that offers deep relaxation for bodies fatigued from outdoor activities. It is highly recommended for those seeking rejuvenation amidst grand nature.

Hakone Yumoto Onsen's history is said to date back to the Nara period, making it Hakone's oldest hot spring village. [2, 4] The Hakone no Yu Kamon source is a private spring drilled in this historic land. This sodium/calcium-chloride/sulfate spring follows in the tradition of famous waters once presented to the Shogun's family during the Edo period. [10] Its waters gently envelop the skin, providing a characteristic warmth that lingers long after bathing. It is recommended for those seeking to release mind and body in historic, nature-rich Hakone.

Hotel New Tsuruta Gensen 1-go is a private source located in the Kitahama area, the central district of the Beppu Onsen region, which boasts the largest volume of hot spring water in Japan. This source feeds the hotel's panoramic bath, known as "Nijo-no-yu," and is descended from a historic spring said to have been flowing since the Tenpo era (1830-1844). The mildly alkaline chloride spring is gentle on the skin and warms the body to its core. It is recommended for those who wish to unwind and experience a moment of luxury while soaking in historic waters with a view of Beppu Bay.

Originating from the fumaroles of Owakudani, born from the eruption of Hakone volcano approximately 3,000 years ago, this artificially developed hot spring began to be supplied to Sengokuhara and Gora by Hakone Onsen Kyokyu Co., Ltd. in Showa 5 (1930). Its renowned milky white waters, blended with naturally gushing spring water, offer a pleasant sensation that tightens the skin and a powerful restorative warmth that penetrates deep into the body's core. After bathing, you'll feel surprisingly refreshed and light. It's a perfect companion when you seek to feel the Earth's energy and achieve deep relaxation and rejuvenation for your mind and body.

Found near the Saga Yamato Interchange, "Yamato no Yu" stands as one of Kyushu's premier high-concentration carbonated springs. This source boasts an impressive 1600mg/kg of carbon dioxide gas, significantly surpassing the legal definition for a carbon dioxide spring of 1000mg/kg. Fresh, pump-lifted water is directly supplied, ensuring its purity. As you immerse yourself in the lukewarm bath, countless silver bubbles envelop your skin, their gentle effervescence stimulating circulation throughout your body. It's an ideal hot spring for those seeking deep relaxation and rejuvenation for both mind and body.