What Do Night Sweats Mean in Chinese Medicine?

If you keep waking up drenched in a cool room, the room is probably not the problem. Chinese medicine has a name for sweat that only comes in your sleep, thief sweat, and a way of asking where it comes from. Here is what the name means, what your brain’s thermostat is doing at night, and the three patterns I look for.

What do night sweats mean in Chinese medicine?

They mean the body is losing its hold at night. The Chinese name is 盗汗, dao han, thief sweat. Like a thief, it comes while you are asleep and is gone by the time you wake up.

That timing is why the tradition keeps it apart from daytime sweating. Sweat that breaks out by day with little effort is zi han, spontaneous sweat, and is read as weak qi failing to keep the surface closed. Sweat that comes only in sleep points somewhere else: to yin, the cooling, moistening, inward side of the body.

The classical picture: by day your defensive qi, wei qi, moves along the surface and keeps the pores in order. At night it withdraws inward into yin, and the surface is left less guarded. If there is heat inside and not enough yin to contain it, that heat steams fluid out through the unguarded skin. When you wake, wei qi returns to the surface, the pores close and the sweating stops. The thief has gone.

The hour a symptom shows up is a clue to the terrain. Reading those clues is what we practice inside Gut Brain Synchrony.

Why do I wake up drenched in sweat?

Because the thermostat in your brain decided you needed cooling, whether or not you did.

Your body is meant to cool down at night

That thermostat is the hypothalamus. The preoptic area at its front handles both body temperature and the switch between waking and sleep, so the two are wired together. As you fall asleep your core temperature drops, partly because the vessels in your hands and feet open and let heat out through the skin.^[1] When it reads too much heat it turns on sweating, which cools you as it evaporates: your body’s own swamp cooler.

So the room does matter. Under bedding and clothing, heat exposure increases wakefulness and cuts deep sleep and REM sleep, and humid heat adds to the load.^[2] But if the room is cool and you still wake up wet, the signal is coming from inside.

How common night sweats are

More common than you might think. In a study of 363 adults seen in 10 primary care offices, 34 percent had night sweats in the past month, and half of them had soaked their bedclothes.^[3] A systematic review put the range at 10 percent of older primary care patients up to 60 percent of women on an obstetrics ward. Many of the people reporting them had none of the conditions usually blamed.^[4]

What can reset the thermostat

Stress, infections and hormone changes can all shift it, and so can things people do not suspect.

The same review found that many suggested causes are not well supported.^[4] Your brain can trigger sweating when you do not need to cool down at all. That gap is what Chinese medicine was built to read.

Why do I sweat at night but not during the day?

Because night is when yin is supposed to be in charge. Chinese medicine describes body temperature as a balance of yin and yang. Yin cools your body. Yang warms it up. At night yang is meant to sink down and rest inside yin. When the balance tips and yang runs too high, the body sweats to correct it.

In the study of older patients, night sweats, day sweats and hot flashes each went with a somewhat different set of other symptoms.^[5] Chinese medicine sees three ways yang ends up too high at night, each treated in a different direction.

Yin too low to anchor yang

This is the classic thief sweat, and the pattern most often seen in perimenopause. Yin, the cooling reserve, has run down, so it cannot hold yang in place, and heat lifts at night with the sweat. The tradition reads this as Kidney yin deficiency, which is also how it reads falling estrogen. The answer is to nourish: herbs like Rehmannia, shu di huang, and Dang Gui rebuild what is missing. The bigger picture of this stage of life is in Why Is Menopause Called the Second Spring?

Yang running too high

Here there is real heat, not only a shortage of cooling. When yang is pushed too high by chronic inflammation, we clear heat with cooling herbs like Bupleurum, chai hu. Signs that go with it are irritability, a flushed face and a bitter taste on waking, which the classics read as heat in the Liver and Gallbladder. The primary care study found that same pairing: people with night sweats had nearly twice the odds of waking with a bitter taste.^[3]

Dampness keeping yang from coming down

The third pattern surprises people. Dampness, the heavy, sticky residue of a digestion that is not keeping up, can sit in the middle and stop yang from descending. The heat trapped above it pushes out as sweat. Nourishing would only add more damp. Instead we dry and open, with herbs like Cang Zhu, atractylodes, and with Tibetan herbal foot soaks to open the channels.

Cang Zhu has antifungal activity in the lab. In immunosuppressed mice given a lethal Candida infection, a water extract of the root prolonged survival, through a polysaccharide in it.^[8] That is a mouse study, not a human one, but it fits how I think about damp: terrain where the wrong organisms thrive.

What Chinese herbs are used for night sweats?

The formula most tied to night sweats is Dang Gui Liu Huang Tang, Dang Gui and Six-Yellow Decoction. It was first recorded in the Lan Shi Mi Cang, a text from 1276, and in 2018 China listed it in its national catalogue of classical formulas.^[9] Dang Gui and both forms of Rehmannia nourish yin and blood. Huang Qin, Huang Lian and Huang Bai clear heat. Huang Qi firms the surface so the sweat stays in. Six of its seven herbs carry huang, yellow, in their names.

A 2020 systematic review found only five randomized trials in menopausal women. Against conventional drugs, the formula may reduce hot flashes, but the certainty was low and the trials had an unclear risk of bias.^[10] In rats with a model of perimenopausal syndrome, it shifted progesterone and estradiol.^[9]

A Cochrane review of 22 trials found little or no difference between Chinese herbal medicine and placebo for hot flushes, and one trial found none for night sweats.^[11] Most of those trials gave every woman the same formula, which is not how the medicine is practiced. In a small Dutch pilot where each prescription was matched and adjusted to the woman’s own Chinese medicine diagnosis, the herbs reduced hot flushes 29 percent more than placebo did, against almost 50 percent for hormone therapy.^[12]

Two single herbs are worth knowing. Fu Xiao Mai, the light wheat grain that floats when the harvest is washed, is the traditional single herb for night sweats, used to calm the Heart and hold in sweat. Suan Zao Ren, the sour jujube seed, calms the mind and also holds in sweat, which I wrote about in Does Jujube Help You Sleep?

Is there an acupressure point for night sweats?

Yes. The classical night-sweat point is Yinxi, Heart 6, on the little-finger side of the inner wrist. The name means yin cleft. A cleft point is where a channel’s qi gathers deep, and in Chinese medicine sweat is the fluid of the Heart. So the yin cleft of the Heart channel is the point for sweat leaking out of yin at night. It is listed for night sweating in the Zhenjiu Dacheng, the great acupuncture compendium of 1601.

How to find Yinxi

Turn your palm up. Feel for the tendon that runs along the little-finger edge of your wrist. Yinxi sits just on the thumb side of that tendon, about half a thumb-width above the wrist crease.

Acupuncture for sweating has been tested, though not this point on its own. In a Danish trial in nine primary care practices, 70 women with moderate to severe menopausal symptoms were randomized to five weekly acupuncture sessions or to wait. After six weeks, the acupuncture group had less day-and-night sweating, fewer hot flushes and fewer menopause-related sleep problems.^[13] The points, on the lower belly and legs, were the same for everyone, so it shows acupuncture can move this symptom, not that one point does.

What causes night sweats, and how do you stop them?

Find the pattern first, then work in its direction.

Night sweats questions, answered

Is it normal to sweat at night while sleeping?

A little, yes. Your body sheds heat as you fall asleep, and a warm room or heavy covers will make anyone sweat. Waking up soaked in a cool room is different. That is thief sweat.

Why do I wake up drenched in sweat but cold?

Because sweat cools you as it evaporates, and your thermostat switched it on when you did not need cooling. You end up wet and chilled at once. Chinese medicine adds that sweat carries yang out with it, which is why a heavy sweat leaves you cold and drained.

Can acupuncture help with night sweats?

For menopausal women, the Danish trial says yes, within six weeks.^[13] I choose points by pattern, as with herbs.

The sweat is not the problem. It is the message.

— Brehan Crawford, L.Ac.

References

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3. Mold JW, Woolley JH, Nagykaldi Z. Associations between night sweats and other sleep disturbances: an OKPRN study. Ann Fam Med. 2006;4(5):423-426. doi:10.1370/afm.554
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8. Inagaki N, Komatsu Y, Sasaki H, et al. Acidic polysaccharides from rhizomes of Atractylodes lancea as protective principle in Candida-infected mice. Planta Med. 2001;67(5):428-431. doi:10.1055/s-2001-15822
9. Xue B, Chen X, Wang X, et al. Application of multivariate statistical analysis and network pharmacology to explore the mechanism of Danggui Liuhuang Tang in treating perimenopausal syndrome. J Ethnopharmacol. 2022;284:114543. doi:10.1016/j.jep.2021.114543
10. Jun JH, Lee HW, Zhang J, Yang F, Lee MS. Herbal medicines (Danggui Liuhuang decoctions) for management of menopausal symptoms: a systematic review of randomized controlled trials. J Clin Med. 2020;9(6):1778. doi:10.3390/jcm9061778
11. Zhu X, Liew Y, Liu ZL. Chinese herbal medicine for menopausal symptoms. Cochrane Database Syst Rev. 2016;3(3):CD009023. doi:10.1002/14651858.CD009023.pub2
12. Kwee SH, Tan HH, Marsman A, Wauters C. The effect of Chinese herbal medicines (CHM) on menopausal symptoms compared to hormone replacement therapy (HRT) and placebo. Maturitas. 2007;58(1):83-90. doi:10.1016/j.maturitas.2007.06.005
13. Lund KS, Siersma V, Brodersen J, Waldorff FB. Efficacy of a standardised acupuncture approach for women with bothersome menopausal symptoms: a pragmatic randomised study in primary care (the ACOM study). BMJ Open. 2019;9(1):e023637. doi:10.1136/bmjopen-2018-023637