Two more people, and then it is your turn to present. The note card with your key points is smudged at one corner from being held too long, and before shaking hands with a new guest, you quietly wipe your palm on your trouser leg. The room is air-conditioned, yet your underarms are still dark with sweat. In most cases, the body is simply doing its job. But in some people, sweating is so heavy that they even dread shaking hands. In others, it is a signal of an illness that needs to be found.
Nervous sweating is driven by the sympathetic nervous system
Most sweat is there to cool you down, as when you go for a run at midday or sit down to a bowl of spicy noodle soup. Sweat from anxiety takes a different route. As soon as the brain reads a situation as pressure, the sympathetic nervous system switches on. The heart beats faster, the muscles tense slightly, and the sweat glands in the palms, the soles of the feet and the armpits are stimulated even though body temperature has not risen. Everyone has this reaction; people differ only in its threshold, and that threshold can be lowered.
Some people start to sweat just hearing their boss’s ringtone. The body can sound the alarm before thought catches up, in the same way we startle at something that only vaguely resembles an old fear. When sweating goes beyond what is needed to regulate body temperature and causes significant emotional, physical or social discomfort, medicine calls it hyperhidrosis (Nawrocki and Cha, 2019); it affects at least 4.8% of the US population. The cause may be an autonomic nervous system that overstimulates sweat glands that are otherwise normal.
Wet hands since school days, and someone in the family is the same
Some people look back and realize their hands have been damp since their school days, when they had to put a tissue under their hand during exams, and when they ask, their mother or an older sibling turns out to be the same. This pattern is usually primary hyperhidrosis, meaning it is not caused by another illness. Walling (2011) reviewed the records of 415 patients and found that 93.3% had the primary form. The author suggests considering this form when excessive sweating has lasted six months or longer, together with at least four of the following features:
- Sweating in the armpits, palms, soles of the feet or face;
- Sweating on both sides, fairly symmetrically;
- No sweating during sleep;
- At least one episode a week;
- Onset at age 25 or younger;
- Someone in the family has it too;
- It interferes with daily life and work.
Sweating patterns that point to another illness
The remaining 7% or so have the secondary form, meaning the sweating is caused by an illness or a medication. This kind usually begins after age 25, is clearly one-sided, affects the whole body instead of a few areas, and also occurs during sleep. In Walling’s study, more than half of the secondary cases were due to endocrine diseases such as diabetes or hyperthyroidism; about a third were due to neurological diseases. Nawrocki and Cha stress that the secondary form must be ruled out before concluding it is primary.
Doctors also often think of low blood sugar and medication side effects. If you have recently changed or added a medication and then notice you are sweating more, tell the person who prescribed it, and check with them before reducing or changing the medication.
Sweating with chest pain, shaky hands or weight loss
Breaking into a cold sweat with chest pain, chest tightness or shortness of breath is a reason to call emergency services (115 in Vietnam); don’t wait for it to pass. People taking diabetes medication who break into a sweat with gnawing hunger, shaky hands or drowsy confusion also need to get to a hospital right away, because this may be low blood sugar.
Night sweats that soak your shirt, with fever or weight loss for no clear reason, or sweating on only one side of the body or one side of the face, call for a doctor’s visit within the week. The same goes for heavy sweating together with a pounding heart, shaky hands or weight loss, because these are the patterns, mentioned above, that suggest the secondary form.
When tests are normal but the sweating continues
Quite a few people bring in blood sugar and thyroid test results that are all within normal limits. In that case, Dr. Dinh Ngoc Duc (MD, MSc in Traditional Medicine) asks when the sweating happens and what you are doing at the time. If the sweating follows the primary pattern, or only flares up under stress, what needs to be found is whatever is holding the alarm threshold low. Applied Kinesiology (AK) adds muscle testing to look at each part, and this testing always goes alongside a medical diagnosis (Rosner and Cuthbert, 2012).
How much stress has built up has to be asked about through concrete events. The doctor often asks at what point last week your hands were wettest, and who you were sitting in front of at the time, then compares this with the examination findings.
Micronutrients also need checking. Long-term stress drains magnesium, and low magnesium in turn makes people more prone to tension. The doctor checks this using the chemistry tests of the health triangle, along with lab tests when needed.
In some people, the doctor also checks the primitive reflexes, because after a long period of stress they can become active again and keep a sense of wariness in place. Not everyone who sweats a lot has this factor.
Sweating that follows worry, seen through traditional medicine
Traditional medicine regards sweat as the fluid of the Heart, so sweat pouring out along with worry is seen as a sign that the Heart is not yet at peace. Sweating during sleep is called night sweating (盗汗 / 盜汗, dào hàn) and usually brings yin deficiency (阴虚 / 陰虛, yīn xū) to mind. Modern medicine also takes this sign seriously, so the doctor asks carefully about fever and weight before discussing the pattern.
For someone whose hands get wet at every meeting, treatment leans toward nourishing the Heart, whether with acupuncture or a herbal decoction, and each person’s treatment is modified in its own way. Night sweating is different: the doctor first looks at the pulse and tongue, and only then considers treating along the lines of yin deficiency. Micronutrients are added when the examination shows a deficiency.
Worth keeping
- For two weeks, note where you sweat, when, and whether you sweat during sleep;
- Ask your parents and siblings whether anyone has had sweaty hands and feet since childhood;
- List the medications and supplements you take, and the date you started each one;
- A few minutes before an important meeting, practice breathing out more slowly and for longer than you breathe in;
- If you break into a cold sweat with chest pain, chest tightness or shortness of breath, call emergency services (115 in Vietnam); don’t wait for it to pass.
References
- Nawrocki S, Cha J (2019). The etiology, diagnosis, and management of hyperhidrosis: A comprehensive review: Etiology and clinical work-up. J Am Acad Dermatol 81(3):657-666. https://doi.org/10.1016/j.jaad.2018.12.071
- Walling HW (2011). Clinical differentiation of primary from secondary hyperhidrosis. J Am Acad Dermatol 64(4):690-5. https://doi.org/10.1016/j.jaad.2010.03.013
- Rosner AL, Cuthbert SC (2012). Applied kinesiology: distinctions in its definition and interpretation. J Bodyw Mov Ther 16(4):464-87. https://doi.org/10.1016/j.jbmt.2012.04.008
