Her baby was four or five months old and still exclusively breastfed when she came to the clinic because she was tired. She said she felt drained all the time, "as if I have no energy in reserve". Cold sweat poured out on her chest and head. In an air-conditioned room the sweating eased, but then her belly felt cold. After breastfeeding she did not feel hungry and had no appetite, even though she still ate three meals a day. Drinking milk easily made her feel bloated.
She had been seeing us since the fourth month of her pregnancy, and at times she had sweated even while she was pregnant. A few days after the birth, the doctor noted that she was exhausted after giving birth and short of blood, and increased the qi-tonifying herbs in her prescription. At this visit, her fingernails and the inner lining of her eyelids were still pink.
A great many mothers sweat after giving birth, and most of the time it is nothing to worry about. What set her case apart was that months had passed and she was still tired and still sweating.
Sweating in the first few days
Traditional medicine books regard a little sweating after birth as normal. That kind of sweating, as Xia Guicheng (夏桂成) describes it, comes as fine beads, sometimes over the whole body, sometimes only on the upper half or only on the head and face, usually during slight exertion or while eating; the amount is small, not enough to need a change of clothes. He calls it a common occurrence after birth that clears by itself within a few days and needs no medicine. His handbook also notes that sweating a little more after activity or during sleep in the first few days is not yet considered an illness. Maciocia, author of an English-language textbook on obstetrics and gynecology in Chinese medicine, also finds that this sweating usually stops on its own after a few days, but states clearly that heavy sweating that goes on is already an illness and should be stopped early.
In the Jīn Guì Yào Lüè (金匮要略 / 金匱要略, Synopsis of the Golden Chamber), Zhang Zhongjing (张仲景 / 張仲景) explains that giving birth causes blood loss, so the yang side (the warm, active side of the body) temporarily gains the upper hand, and sweat comes out to bring yin and yang back into balance. It is the body rebalancing itself in the first few days, but too much sweating is not a good thing. The classical Vietnamese physician Hai Thuong Lan Ong, in his section on sweating from deficiency after birth, considers heavy sweating on top of blood loss to mean that both yin and yang are deficient, which is very dangerous.
Modern medical literature has few studies on this specifically. A group in the US followed 429 mothers through the first year after birth and found that about 3 in 10 mothers at some point had hot flashes that disturbed their sleep. At the first interview, in the second week after birth, around 1 in 5 mothers had such episodes; the number then fell gradually, to about 1 in 10 by the end of the year (Thurston 2013). This study asked about hot flashes that disturbed sleep rather than measuring sweat, and quite a few mothers in the group had had depression or bipolar disorder, so the figures are only estimates. The same study did not find that breastfeeding made these episodes more frequent.
Sweating in the first weeks is usually explained by the rapid drop in hormones after birth, at the same time as the body readjusts the fluid it built up during pregnancy (Thurston 2013; StatPearls). This explanation is widely held, but no study has measured it directly.
The books say "a few days", while in the study above hot flashes went on for many weeks in quite a few mothers, so it is easier to watch whether you are sweating a lot or a little, and whether it is easing or getting worse, than to count days. If the sweating is moderate, you haven’t had to change your top several times, and it is easing day by day, you can wait with peace of mind.
Spontaneous sweating and night sweating
When sweating becomes an illness, traditional medicine books divide it into two kinds. Spontaneous sweating (自汗, zì hàn), according to Xia Guicheng, is dripping sweat that does not stop, gets heavier with movement, and sometimes keeps coming even while you lie quietly in bed. Night sweating (盗汗 / 盜汗, dào hàn, literally "thief sweating") means that as soon as you fall asleep, sweat breaks out all over and soaks your clothes, then stops when you wake. Fu Qingzhu (傅青主) likens sweating during sleep to a thief who waits for people to fall asleep. The two kinds can come separately or together.
Both have their root in the way giving birth drains qi and injures blood. When qi and blood are damaged, the couli (腠理, còu lǐ), that is, the skin and the grain of the flesh on the outside, is no longer tight, so sweat escapes easily; that is how Chai Songyan (柴松岩) explains it. Xia Guicheng makes a very down-to-earth observation: with spontaneous sweating, slight exertion makes the sweating worse; with night sweating, being upset makes it worse.
You can watch for these yourself:
- Sweating while you are awake, holding the baby, walking around or breastfeeding, that does not stop even when you lie still, is closer to spontaneous sweating;
- Sweating while you are asleep that stops when you wake, and finding your top wet in the morning, is closer to night sweating;
- Having both kinds is not unusual; the books note that they can come together;
- If you sweat in a stuffy room, or because you are dressed too warmly or covered up too much, don’t rush to call it an illness: Xia Guicheng advises that in hot weather you first check whether the room is poorly ventilated and whether you are being kept too warm.
The information page of the UK National Health Service (NHS) gives an easy marker. Many people sweat a little in their sleep; night sweats worth paying attention to are when your nightclothes and bedding are soaked even though the place you sleep is cool.
Try writing things down for a few days: when the sweating happens, where (head, chest or whole body), how many times a day you change your top, and whether you have to get up at night to change. Those few lines help the doctor more than "I’ve been sweating a lot lately".
Sweat is the fluid of the Heart (the Heart organ, which traditional medicine links to the heart and the mind), Xia Guicheng writes, so "irritability and anger, tension and fear make the Heart’s fluid spill out even more", and treatment must include explaining things to the patient and comforting her. In Thurston’s study, symptoms of depression were also the factor most clearly linked with night-time hot flashes after birth, and the NHS lists anxiety among the common causes of night sweats. If you are sad or worried, say so, even when you come in about sweating.
Where normal ends and illness begins
Xia Guicheng draws the line quite clearly. Soaking your undershirt while lying still, and having to change several times a day, means it has become an illness. Discussing a case of sweating that had lasted nine months, Chai Songyan’s book of case records says that this "is no longer a normal state". Most of these cases, Xia Guicheng notes, can be cured with treatment.
Many people don’t expect traditional medicine books to call for tests as well. Besides the usual examination, Xia Guicheng writes, depending on the situation, one may choose tests such as thyroid function, erythrocyte sedimentation rate, a chest X-ray and a tuberculosis test, to rule out other diseases. Heavy sweating after birth needs to be told apart from hyperthyroidism, tuberculosis and illnesses with fever. For long-lasting night sweats, he advises a chest X-ray. The book says "depending on the situation", so the doctor chooses tests for each person; not every mother who sweats is the same.
The thyroid after birth
Postpartum thyroiditis affects about 5 to 10 in 100 mothers (ATA; StatPearls). It usually goes through two phases. In the first phase, about 1 to 4 months after birth, you may feel anxious, sleep poorly, have palpitations, feel tired, lose weight, be irritable and feel hotter than other people, or you may have no symptoms at all. In the second phase, about 4 to 8 months after birth, the thyroid is underactive, and you feel tired, dislike cold, have dry skin and feel low. The American Thyroid Association (ATA) points out that these symptoms are easily mistaken for tiredness from caring for a baby, so the condition is often missed.
The ATA information page on this condition does not list sweating among the symptoms. Sweating alone cannot tell you whether there is a thyroid problem; a blood test is needed. When sweating comes with signs of either phase, or with shaky hands, the doctor will usually order a thyroid function test.
Bring up your thyroid with your doctor yourself if:
- You have type 1 diabetes, because the risk of postpartum thyroiditis is about 3 times higher (Stagnaro-Green 2004);
- You have another autoimmune disease (a disease in which the immune system mistakenly attacks your own body);
- You have had thyroid disease before;
- You had thyroiditis after a previous birth, because about 20 in 100 women get it again after the next birth (ATA);
- Someone in your family has thyroid disease;
- Tests during pregnancy found thyroid antibodies, because up to half of mothers with them develop postpartum thyroiditis (Stagnaro-Green 2012).
If it does turn out to be this condition, the doctor has medicine to calm palpitations that can be used while breastfeeding. Some mothers remain hypothyroid (with an underactive thyroid) in the long term after the underactive phase (ATA), so follow-up checks as scheduled are needed. For which tests to do before taking tonics, see the article in this series on tests for mothers who stay tired after birth.
Care at home
If you sweat a lot, drink enough, and keep a cup of warm water where you breastfeed (NHS). Warm water with a little sugar and a little salt is better than gulping down large amounts of plain water or tea (Xia Guicheng). Forcing yourself to drink lots of water does not increase your milk either (Ndikom 2014; Dusdieker 1985).
When you sweat, wipe yourself down with a towel dipped in warm water and change into a dry top; don’t sit in a draft while you are drenched in sweat. Hai Thuong has a health saying, "while sweat is pouring out, do not hurry to take off your clothes", so dry yourself and change somewhere out of the wind. There is no need to make a point of wearing very thick clothes; eat enough nourishing food, and walk and move as much as you comfortably can (Chai Songyan). Maciocia also advises mothers not to overexert themselves. How much wrapping up and avoiding wind is right during the postpartum "confinement" period (ở cữ) is discussed in detail in the article in this series on avoiding wind and keeping warm during confinement.
Seeing a mother weak and drained, many families immediately think of warming tonic dishes. Treating a mother who had sweated heavily for several months after birth, Chai Songyan advised that although she was deficient, warming tonic herbs should not be used much, and her diet should also avoid warming foods such as red dates, black-skinned silkie chicken and longan. Xia Guicheng also records a case in which a woman drank pot after pot of soup stewed with tonic herbs, and her sweating only got worse.
Leave herbs that stop sweating to the physician, who will choose them and set the dose to suit a breastfeeding mother; don’t buy them yourself. Commenting on a case of low milk supply, Chai Songyan wrote, "do not astringe sweat too much, to guard against reducing the milk" (to astringe means to draw in, to hold sweat back; 敛汗 / 斂汗, liǎn hàn), and reminded readers that prescribing during breastfeeding must take the nursing baby into account.
When to call the clinic, and when to see a doctor right away
Let the clinic know, book a visit and possibly have tests (no emergency care needed yet) when:
- You soak your top even while lying still, or every night you soak your nightclothes and bedding even though the room is cool, enough to wake you up;
- The first weeks have passed and the sweating has not eased, or after a few months it suddenly becomes heavy again;
- The sweating comes with palpitations, shaky hands, rapid weight loss, restlessness and poor sleep, or feeling hotter than other people, or with long-lasting exhaustion, feeling cold and dry skin;
- The sweating comes with long-lasting sadness, anxiety or loss of interest;
- Night sweats come with a lingering cough, fevers in the afternoon or unexplained weight loss;
- You are taking medicines such as antidepressants, corticosteroids or painkillers and the sweating has increased; in that case ask the person who prescribed them, and don’t stop the medicine on your own (NHS);
- The sweating comes with strong thirst and a low, simmering feverish feeling; in that case take your temperature and let us know early.
The lương y (traditional medicine practitioner) Nguyen Huu Duc warns that "sweating with thirst is a bad sign", because it may mean a fever is coming, and by the time the chills set in it is already late.
If you are drenched in sweat and also drowsy, panicky or have cold hands and feet, or if the sweating comes with fever, chills, belly pain or foul-smelling lochia, see a doctor right away. Other signs that also need immediate care are in the article "Warning signs after birth that need care right away".
Back to her story
Set against the traditional medicine books, her kind of sweating is close to spontaneous sweating from qi deficiency, meaning the body’s qi, its strength, is weak. Xia Guicheng describes this pattern as sometimes having sweating on the head, shortness of breath and a weary spirit. The clinic prescribed her a formula mainly to tonify qi, strengthen the Spleen (make the Spleen, which handles digestion in traditional medicine, stronger) and nourish blood, with herbs to help hold in sweat and calm the mind, at a moderate level because she was breastfeeding.
What to bring to your visit
If the sweating and tiredness keep dragging on, you can come in to the clinic. Bring your notes on sweating, the medicines you are taking and any test results you already have. The doctor will ask more about your sleep, your milk and your mood lately, look at your tongue, take your pulse, and review your old prescriptions if you have been seen here before.
Some mothers have tests that come back within normal limits, yet they still feel drained and keep sweating. In that case the doctor may also use Applied Kinesiology (AK), which means testing muscle strength by hand to see how the different parts of the body are working together. Walther’s AK textbook describes people whose blood sugar swings up and down: when the blood sugar drops low, the heart races, they break out in a cold sweat, tremble and feel restless. He observes that a stressful event, sadness or worry can set off such episodes, but the root is the adrenal glands (small glands on top of the kidneys that help the body cope with stress) no longer being able to carry the load of stress (Walther 2000, p. 520).
That is why the doctor asks in detail about your mealtimes, which meals you tend to skip because you are busy with the baby, and your sleep at night. The doctor also tests the muscles that AK links to the adrenal glands, and tests muscle strength while you think about what is worrying you. You only need to think about it; you don’t have to put it into words. This goes alongside the thyroid test and the other tests mentioned above; it does not replace them.
References
Sources in Vietnamese
- Nguyễn Hữu Đức. 2017. Các bài thuốc Nam gốc (bài giảng). Tr. 22.
- Hạ Quế Thành. Sổ tay chẩn đoán điều trị phụ khoa (bản dịch tiếng Việt). Tr. 345–346.
- Hạ Quế Thành. Thực dụng Trung y phụ khoa học (bản dịch tiếng Việt của BS. Tâm). Tr. 456–458, 460–461.
- Hải Thượng Lãn Ông. Hải Thượng y tông tâm lĩnh. Hà Nội: NXB Y học. Tập 1, tr. PDF 885; tập 2, tr. PDF 422.
- Phó Thanh Chủ. Phó Thanh Chủ nữ khoa (bản dịch tiếng Việt). Tr. PDF 370.
- Sài Tùng Nham. Kinh nghiệm lâm sàng và nghiệm án (bản dịch tiếng Việt). Tr. 168–169.
- Sài Tùng Nham. Tư biện phụ khoa (bản dịch tiếng Việt). Tr. 249, 251–252.
- Sài Tùng Nham. Tư biện phụ khoa, bản in lần 2 (bản dịch tiếng Việt). Tr. PDF 154, 156–157.
Sources in English
- American Thyroid Association. Postpartum Thyroiditis [Internet; patient information]. Available from: https://www.thyroid.org/postpartum-thyroiditis/.
- Carlson K, Mikes BA. 2025. Postpartum Thyroiditis. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. PMID: 32491578.
- Dusdieker LB, Booth BM, Stumbo PJ, Eichenberger JM. 1985. Effect of supplemental fluids on human milk production. J Pediatr. 106(2):207-11. doi:10.1016/s0022-3476(85)80288-2. PMID: 3968608.
- Kunarathnam V, Carlson K. 2026. Physiology, Postpartum Changes. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. PMID: 32310364.
- Maciocia G. Obstetrics and Gynecology in Chinese Medicine. Chapter 49, p. 625–628.
- Ndikom CM, Fawole B, Ilesanmi RE. 2014. Extra fluids for breastfeeding mothers for increasing milk production. Cochrane Database Syst Rev. 2014(6):CD008758. doi:10.1002/14651858.CD008758.pub2. PMID: 24916640.
- NHS. 2023. Night sweats [Internet; page last reviewed 2023 Nov 9]. Available from: https://www.nhs.uk/conditions/night-sweats/.
- NHS. 2026. Breastfeeding and diet [Internet; page last reviewed 2026 May 15]. Available from: https://www.nhs.uk/baby/breastfeeding-and-bottle-feeding/breastfeeding-and-lifestyle/diet/.
- Stagnaro-Green A. 2004. Postpartum thyroiditis. Best Pract Res Clin Endocrinol Metab. 18(2):303-16. doi:10.1016/j.beem.2004.03.008. PMID: 15157842.
- Stagnaro-Green A. 2012. Approach to the patient with postpartum thyroiditis. J Clin Endocrinol Metab. 97(2):334-42. doi:10.1210/jc.2011-2576. PMID: 22312089.
- Thurston RC, Luther JF, Wisniewski SR, Eng H, Wisner KL. 2013. Prospective evaluation of nighttime hot flashes during pregnancy and postpartum. Fertil Steril. 100(6):1667-72. doi:10.1016/j.fertnstert.2013.08.020. PMID: 24035604.
- Walther DS. 2000. Applied Kinesiology: Synopsis. 2nd ed. Pueblo (CO): Systems DC. p. 512, 520.
Sources in Chinese
- 张仲景. 金匮要略. 妇人产后病脉证治, PDF 第 50 页.
