What are the health benefits of Japan's traditional hot springs?

Onsen offers numerous benefits from being in the water, as it can allow you to feel lighter, as though you are able to float, which can help to release stress, tension, and relax your entire body.

The heat from Onsen is known to help relieve muscle or joint pains, as the heat of the water works to expand the blood vessels, decreasing inflammation and pain from aching and swollen muscles. 

The thermal heat it produces makes these hot springs an energy consumption activity, which can speed up your metabolism. A 20-minute session in an onsen with 42-degree Celsius water, has been known to burn over 200 calories. 

Onsen can contain various different minerals such as calcium, sodium bicarbonate, sulphur, and iron. This not only improves general blood circulation and oxygen flow, but also provides a range of health benefits. There are various types of Onsen with differing minerals and thereby, health benefits.

Specifically, those containing sulphur and calcium are particularly beneficial for people suffering with dry skin conditions such as chronic dermatitis (eczema), or psoriasis. Sulphur has also been recognised for helping to reduce Hypertension (high blood pressure) as well as Arteriosclerosis, a type of vascular disease.

Onsen that is high in copper, magnesium, and iron, can help to improve anaemia and even the menstrual cycle. Therefore, they are sometimes even referred to as “Kodakara no Yu (childbirth ONSEN)” because of their effectiveness in helping to treat menstrual disorders.

Depending on the geographical location of the Onsen, effects and benefits can differ. For example, hot springs located in mountain areas are recommended for different reasons to those located on lower ground in ocean regions.

An Onsen that is located at high altitudes (over 1,000 metres above sea level), is recommended for energetic people as it can stimulate bodily functions, whereas an Onsen that is situated at middle altitudes (up to 300 metres) is known to be effective for those suffering with insomnia or high blood pressure, and those who need rest.

However, an Onsen that resides in ocean areas can be beneficial for those with chronic fatigue, the elderly, and those who may be recovering from illnesses, as this environment has a warmer, more gentle climate.

Hakone’s hot springs are situated in Kanagawa Prefecture, and offer visitors a combination of tranquillity, culture, and a beautiful landscape. Its proximity to Tokyo is a bonus, alongside its amazing views of Mount Fuji. Hakone offers a variety of hot spring resorts, each offering unique bathing experiences.

Located in the middle of Kyushu, Kurokawa Onsen is known for being one of the most scenic hot spring destinations in the country. Visitors can purchase a special "wooden tegata pass” that allows them to try out several of the different hot spring baths in town.

The town itself has made an effort to maintain a pleasant, traditional atmosphere in the spirit of its bygone days. You'll find a townscape celebrated with natural colours and materials, wooden buildings, earthen walls, and stone steps. There's a river flowing through to complete the scenic picture, lit up with glowing lanterns.

Kusatsu Onsen is one of the most famous hot spring resorts in Japan, and is known for its warm, acidic water, which is sourced from underground streams heated by geothermal activity.

It is so hot that a special stirring procedure is used to cool it, rather than adding cold water, which would dilute the potency of the minerals. This stirring method is called yumomi and is even exhibited as a performance at certain times.

Beppu is known as the hot spring capital of Japan, boasting the largest volume of hot spring water in Japan. A wide variety of baths are offered in Beppu, Oita, such as mud and sand baths. 

Hyotan Onsen is a public bathhouse offering a wide variety of natural spa-like experiences, all driven by a local hot spring. It offers both indoor and outdoor baths, plus a waterfall feature, where you can get your shoulders massaged by the cascading waters. Visitors can enjoy both steam baths and sand baths here, where the sands are heated by natural thermodynamics.

Haroun Khan at Japan Rail Pass provides expert commentary on the popularity of Onsen, as well as tips on etiquette:

“Hosting over 27,000 Onsen across the country, Japan is famous for the best hot springs in the world. Onsen can be traced back thousands of years within Japan’s history, and has recently become a popular travel and wellness trend, as people look to experience the various healing qualities of these hot spring destinations.

“If you plan to visit an onsen, it is a good idea to research the etiquette required and check the rules and regulations for the onsen you are visiting. Some onsens have rules about displaying tattoos for example, so it is always best to check ahead of time.”