Hot springs in TCM: cold-damp, qi and what research shows

Traditional Chinese Medicine (TCM) treats hot spring bathing, 温泉疗法 (wēnquán liáofǎ), as a strong heating therapy for stiff joints, numbness and skin disease, not as an everyday wellness habit. The classical texts prescribe it as a bath, and say to follow a soak with medicine and nourishing food because it leaves you drained [1]. Modern research supports part of this, mainly what heat does to circulation and sore joints, but not the theory of qi and meridians behind it.

Below: what the old texts actually say, where their ideas line up with current research and where they don’t, and what that means at Malaysian springs. The evidence grade here is traditional. These are long-standing practices, not tested treatments.

What does Traditional Chinese Medicine say hot springs treat?

The best-known entry is in Li Shizhen’s Ming-dynasty Ben Cao Gang Mu (本草纲目, Compendium of Materia Medica), in the chapter on waters. Li files hot spring water under 温汤 (wēntāng), with the other names 温泉 (hot spring) and 沸泉 (boiling spring) [1].

He describes its nature as acrid, hot and slightly toxic (辛，热，微毒). Quoting the Tang-dynasty scholar Chen Cangqi, he lists what bathing in it is for [1]:

• wind disorders with cramped, contracted sinews and bones (诸风筋骨挛缩)
• stubborn numbness of the skin and flesh (肌皮顽痹)
• hands and feet that won’t move as they should (手足不遂)
• loss of eyebrows and hair
• scabies, ringworm and other complaints “in the skin and joints”

The entry ends with two cautions that rarely appear in spa brochures. After bathing, the patient will be “greatly drained”, so they should be given medicine suited to their illness and nourishing food. And people who are not ill “should not enter lightly” (非有病患，不宜轻入) [1].

Li also passes on an account from Lushan, a mountain in Jiangxi. Practitioners there told patients with scabies, leprosy-like skin disease and syphilitic sores to eat a full meal, then soak until they sweated, and they were said to recover in about ten days [1]. Read that as history, not a result. These are infections that modern medicine treats with drugs.

Hot springs in classical Chinese texts

Li was drawing on a long written record. A history of Chinese hot spring therapy, published in a Chinese medical history journal, traces it back to the Wentang Stele, which described sulphur springs as able to treat disease, and to a hot spring poem (温泉赋) by the Han-dynasty writer Zhang Heng [2].

Later writers became more systematic [2]:

• The Northern Wei geography Shuijing Zhu recorded hot springs in 41 places.
• The Tang-dynasty Bencao Shiyi discussed how hot springs form and what they treat.
• A Song-dynasty materia medica advised combining hot spring bathing with diet.
• The Ming-dynasty Shiwu Bencao sorted springs into sulphur, arsenic, cinnabar and alum types, each with its own uses.

An illustrated Ming copy of the Shiwu Bencao, now in the Wellcome Collection, calls warm spring water hot in nature and poisonous, and says it should not be drunk. It also warns that people who are physically weak or debilitated should be careful about bathing in it [3].

Historian Fei Huang argues that premodern Chinese writers used hot springs to think about how nature and the body interact, in ritual, literature and daily life as well as medicine [4].

Cold, damp and blocked qi: why TCM uses heat

The joint and numbness complaints in the hot spring entries belong to a TCM category called bi (痹), usually translated as “impediment” or “obstruction”. The Huangdi Neijing gives it a whole chapter, which opens with the line: wind, cold and damp arrive together and combine to form bi (风寒湿三气杂至，合而为痹) [5].

The chapter sorts bi by which of the three dominates [5]:

Dominant factor	Type of bi	Usual reading of the name
Wind	行痹 (moving bi)	Pain that wanders
Cold	痛痹 (painful bi)	Pain; the text says “where there is pain, cold is greater”
Damp	着痹 (fixed bi)	Symptoms that lodge in one place

It explains cold-type bi as too little yang and too much yin, and numbness as nourishing and defensive qi (营卫) moving sluggishly, so the skin is no longer fed. It also says that bi of every kind slackens when it meets heat (逢热则纵) [5].

Put together, a hot spring in TCM terms is a strong yang, warming treatment. It is meant to drive out cold and damp, open the channels (经络, the meridians) and get qi and blood moving again. That framing also explains the classical caution: a treatment strong enough to shift a stubborn blockage can drain someone who is already weak.

The same chapter also describes a “hot” bi, where yang is in excess [5]. By the tradition’s own logic, heat answers the cold, damp picture, not every painful joint.

Where modern research agrees with TCM, and where it doesn’t

Several TCM observations match things researchers can measure. The explanations behind them mostly don’t.

TCM idea	What research shows	How solid
Heat moves qi and blood	In shoulder-deep water, cardiac output rose considerably at 40°C but not at 34°C or 25°C [6]. In 8 people sitting in 35°C spa water for two hours, cardiac index rose 50% and urine output doubled [7]	Measurable effect, small physiology studies
Hot bathing eases stiff, painful joints	A meta-analysis of 8 trials found spa bathing reduced knee arthritis pain and stiffness and improved function, but results varied widely between studies [8]	Some evidence for knee arthritis, but trials disagree; never tested on TCM patterns
Sulphur in the water heals sores and scabies	Sulphur is antifungal, antibacterial and peels skin, and was widely used for scabies [9]. The benefits of sulphur spring water itself are “still poorly documented” [10]	Limited for spring water
Sulphur underground heats the water	Sulphur is not a heat source. Peninsular springs are non-volcanic, sit near granite bodies, and their water circulates along major faults [11]	Wrong
Meridians carry qi	No anatomical structure proposed so far meets the definition of a meridian; nerves are the best-supported explanation for acupuncture effects [12]	No physical evidence
Springs near arsenic are poisonous to bathe in	Arsenic is mainly a drinking-water danger; WHO says high-arsenic water can still be used for bathing [13]	Partly right: don’t drink it
A soak drains you; the weak should be careful	Hot water puts real load on the heart [6], and bath-related deaths cluster in older people with heart disease [14]	Supported

Circulation: the clearest overlap

Heat opens up blood vessels near the skin and makes the heart pump more, which is the closest modern match to “moving qi and blood” [6]. A Japanese study that followed 30,076 adults aged 40 to 59 for about 20 years found that people who soaked in a hot bath at home almost daily had 28% lower risk of heart disease and stroke than those bathing twice a week or less [15].

That study is observational, so daily bathers may differ in other ways, and it was about home baths, not hot springs. Qi is also a concept from a different system of thought. Blood flow is part of what TCM means by it, not the whole of it.

Joint pain: promising, but not tested the TCM way

The knee arthritis meta-analysis pooled 8 trials with 359 treated patients and 375 controls. It found less pain and stiffness and better function, measured 2 to 12 months after treatment, but the studies were so inconsistent that the authors only said spa bathing “may” help [8]. We found no English-language trial that grouped patients by TCM pattern, such as cold-damp bi versus hot bi, and then tested hot spring bathing.

Sulphur: right ingredient, wrong dose

Chen Cangqi reasoned that sulphur treats sores, so sulphur water should too [1]. Sulphur does have a real record in skin medicine, but as concentrated preparations put directly on the skin [9]. A review of sulphur spring water says the water needs a fair amount of dissolved hydrogen sulphide, and so a fairly acidic pH, to have any effect. It adds that the skin benefits are “still poorly documented” because double-blind studies are lacking [10]. The inland Malaysian springs in the table below are close to neutral and low in sulphur.

Is hot spring water safe to drink?

No. The Ming Shiwu Bencao says it should never be drunk [3]. Li Shizhen even warned that springs near arsenic-bearing rock are poisonous to bathe in [1]. Modern data puts the risk mainly in drinking. Water sampled at Sungai Klah (Felda Residence) and Ulu Slim contained 0.07 and 0.03 mg/L of arsenic [16], above the WHO recommended drinking-water limit of 0.01 mg/L [13]. Soak in it, don’t drink it.

Who should be careful

The classics’ warning about the weak holds up. Medical examiners in Tokyo reviewed 3,289 bath-related deaths over three years. Most were over 60 and happened in winter. Of the 550 autopsied, 79% showed signs of inhaling water, circulatory disease was the most common contributing finding, and a quarter had a blood alcohol level above 0.5 mg/mL [14].

Check with a doctor before soaking if you:

• are older, frail or recovering from illness. The Shiwu Bencao singled out the weak and debilitated [3], and the Tokyo data points the same way [14]. Don’t bathe alone.
• have heart disease or blood pressure problems. Hot water raises the heart’s workload [6] [7].
• are pregnant. Hot tub use in early pregnancy was linked to 2.8 times the risk of neural tube defects in a study of more than 23,000 women [17].
• have a sudden hot, swollen joint. It can be infection or gout, so get it checked first. The TCM tradition also separates “hot” bi from the cold-damp kind that heat is meant for [5].
• are being treated for a condition. The Ben Cao Gang Mu pairs bathing with medicine and food, never in place of them [1]. Keep taking what your doctor or TCM practitioner prescribed.

And skip alcohol before and during a soak. A quarter of the autopsied Tokyo cases had been drinking [14].

TCM and hot springs in Malaysia

Traditional medicine is widely used in Malaysia: a 2004 nationwide survey found high use of traditional and complementary medicine, mostly herbal [18]. But we could not find any published study on how TCM practitioners here use or prescribe hot springs. What you hear at a spring about soaking out “wind” or aches is community practice, not documented clinical use.

The water also differs from what the old texts described. A 2017 USM PhD thesis mapped 60 hot springs in Peninsular Malaysia and found all of them non-volcanic [11]. Here is what one laboratory study found at six of them [16]:

Spring	Water temperature at sampling	Total sulphur (mg/L)	Arsenic (mg/L)
Ulu Slim, Perak	90°C	5.2	0.03
Sungai Klah, Perak	75°C	3.9	0.07
Dusun Tua, Selangor	70°C	2.7	under 0.01
Sungai Serai, Selangor	43°C	0.5	under 0.01
Semenyih, Selangor	43°C	1.1	under 0.01
Ayer Hangat, Langkawi	45°C	477	under 0.01

The inland springs are low-mineral, near-neutral water (pH 6.9 to 8.2), so at these springs the heat is doing the work, not the sulphur. Ayer Hangat is the exception: salty water with 947 mg/L of sulphate, which the authors link to seawater, since the spring is on an island [16]. It is closed for redevelopment as of 2026, so check its page before going. Sulphate is a different form of sulphur from the hydrogen sulphide that the sulphur spring review describes as the active one [10].

Using a hot spring the TCM way, sensibly

• Pick your pool by temperature. Water at Ulu Slim and Sungai Klah ranged from 80 to 110°C and 60 to 110°C [16]. Bathe only where it has cooled or been mixed, and test it with your hand first.
• Keep soaks short, then rest. The Ben Cao Gang Mu’s “greatly drained” warning is good advice: get out, cool down, drink water and eat [1].
• Think in courses, not single visits. The knee trials looked at treatment lasting two weeks or more [8].
• Bathe in it, never drink it [3] [16].
• Use it alongside treatment, not instead of it. That is what the classical texts themselves recommend [1].