Sweating a Lot for No Reason: Why? (+ What to Do?)

sweating a lot for no reason

Do you sweat excessively for no apparent reason, without exertion, even when it’s not necessarily hot? This is known as hyperhidrosis: excessive sweating.

In this article, I address this phenomenon: why do some people (male or female) experience it? Is it common? What are the solutions?

💬 The comment section is there for you! Feel free to share your experiences, as they can be valuable to others.

♻️ Last update: september 2023
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Sweating a loft for no reason: you’re not alone!

Every month, hundreds of people search for explanations for their excessive sweating without reason. And this even in the middle of winter!

reasons for sweating for no reason
Thousands of people, even in the middle of winter, search for information every month about their excessive sweating for no apparent reason (with wording like “breaking out in a sweat for no reason”, “perspiring for no reason”, “sweating suddenly for no reason”)

When temperatures rise, this number is even higher.

It is reasonable to think that if you are looking for information on this subject, you probably have what is called ‘hyperhidrosis.‘ A complicated word that simply means ‘excessive sweating.

It is estimated that approximately 3% of people in France or United-States, as in other countries around the world, have hyperhidrosis. But this percentage can vary depending on the definition and criteria used to diagnose the condition.

But if so many people suffer from excessive sweating, why don’t you know anyone with this condition? I have two explanations that seem plausible to me:

  • Sweating is really a taboo subject, almost shameful. 50% of people wait 10 years before consulting a doctor for this problem!
  • Some people tolerate the impact of this excessive sweating on their lives much better than others.

About 3% of the global population sweat a lot with no reason: this is what we call hyperhidrosis.

Why do we usually sweat during physical activity?

Before we understand why some people sweat without effort and other reason, let’s first understand the role of sweating, both at rest and during physical activity.

The role of sweating in humans and animals Humans and animals sweat to regulate their body temperature. To ensure that our organs 🧠🫀 function properly, our temperature must remain stable!

Therefore, we have various mechanisms that automatically come into play without us having to think about it to:

  • Raise our temperature;
  • or lower it.

These are mechanisms of thermoregulation = temperature regulation.

Sweating is one of the mechanisms of thermoregulation.

It helps cool the skin by evaporating water on the skin’s surface.

When the body heats up, for example, during physical exercise or in high temperatures, sweat glands located under the skin produce sweat. This sweat is then transported to the skin’s surface, where it evaporates, cooling the body by taking away heat.

Why does sweating become excessive during physical activity?

Sweating becomes excessive during physical activity because physical exertion raises body temperature. Why? Because our muscles generate heat when they function.

Tiny receptors placed all over the body send a message to the brain: ‘Attention, temperature is rising!’

Sweat glands are connected to the brain by nerves. They then receive the information (called a stimulus) that tells them ‘sweat!’

They then secrete sweat.

The more intense the effort, the higher the body temperature rises, and the more sweat glands produce sweat. That’s why we sweat more profusely during intense physical activity.

causes of sweating for no reason

Why do some people sweat even without effort (for no reason) ?

You are here precisely to find out why some people ALSO sweat without any effort. And fot no other reason.

This is related to a malfunction of the sweat glands: they produce more sweat than necessary, they activate more easily and quickly. Therefore, this is called hyperhidrosis, the most common sweating problem.

Excessive sweating can be general or localized to the armpits, hands, feet, face, or other parts of the body like groin, buttocks, etc.

It can have medical causes, but often it has no identifiable cause.

The most common “cause” (90%): primary hyperhidrosis

Primary hyperhidrosis is a type of excessive sweating that occurs without any apparent medical reason. It is a genetic condition and is diagnosed when people sweat excessively in at least two specific areas of the body, usually:

  • Armpits,
  • Hands,
  • Feet,
  • And the thoracic region (the chest, breast, or back).

It is often triggered by situations of emotional stress or changes in ambient temperature (especially if there is little air), but it can also occur randomly.

Hyperhidrosis can have a significant impact on the quality of life of those who suffer from it.

Less common causes (10%): secondary excessive sweating

Secondary hyperhidrosis is a type of excessive sweating caused by:

  • An illness;
  • Medication (such as antidepressants, hypertension medications, among others);
  • Physical characteristics (obesity) or environmental factors (alcohol consumption or certain drugs). There are many medical conditions that can cause excessive sweating, including:
  • Thyroid disorders,
  • Diabetes,
  • Certain types of cancer (see cancer and excessive sweating),
  • Menopause, etc. A doctor can assess the underlying cause if a person experiences sudden or unusual excessive sweating.

The treatment for secondary hyperhidrosis involves treating the underlying condition, in addition to treating the excessive sweating itself.

See also my more comprehensive article on the 6 most common causes of excessive sweating (soon in English).

What to do if this sweating is too bothersome?

If your sweating has a significantly negative impact on your life, there are various options available to you.

Discuss it with a healthcare professional about excessive sweating

A healthcare professional can offer you:

  • Diagnosis: to determine whether you have primary or secondary hyperhidrosis. They can also recommend additional tests to rule out other possible causes of excessive sweating if primary hyperhidrosis is not obvious;
  • Treatments and an assessment of the benefit-risk balance of each one in your case, based on your personal preferences. They can help you decide which treatment is most suitable for you based on your situation;
  • More general support: hyperhidrosis can have a significant impact on the quality of life of those who suffer from it. It can cause embarrassment, discomfort, and make people less confident in social situations.

    Healthcare professionals can help you manage the emotional consequences of excessive sweating and find ways to feel better about yourself;
  • Follow-up: to check the effectiveness of the treatment and make adjustments based on the progression of the condition or any side effects.

See also: How to find a sweating doctor?

Try some tips against excessive perspiring

There are several tips for reducing excessive sweating that do not require medical or surgical treatments. Here are some examples:

  • Hygiene: Keep your body clean and fresh by regularly taking a shower or bath, using mild soaps, and changing your clothes regularly. Of course, this does not mean that hyperhidrosis is a hygiene problem at all!
  • Clothing: Wear clothes made from natural materials like cotton, silk, or linen that allow the skin to breathe. Avoid synthetic materials that prevent air circulation.
  • Diet: Avoid spicy foods, as they can increase sweating. Drink enough water to stay hydrated, but avoid alcoholic and caffeinated beverages, which can increase sweating.
  • Activities: Plan your activities to avoid times of intense heat. If possible, do your most strenuous activities when temperatures are cooler. Even if hyperhidrosis is not solely due to sweating, this doesn’t help!
  • Antiperspirant: Use a deodorant or antiperspirant to reduce the odor of sweat.
  • Relaxation: Take time to relax and manage emotional stress, which can increase sweating. Try meditation, deep breathing, cognitive-behavioral techniques to help you relax. However, their effect on hyperhidrosis has not been evaluated in studies.
  • Ventilation: You may have already noticed that you sweat less in a well-ventilated room, with a fan or natural air. Indeed, air allows sweat droplets to evaporate more quickly. Some people with hyperhidrosis live with a fan always at hand, even at work!

Consideration of treatment for sweating

There are several medical and surgical treatments for excessive sweating, such as:

  • Antiperspirant medications: These are often anticholinergic drugs: glycopyrrolate or oxybutynin are the most common. They block the action of acetylcholine, a chemical that stimulates sweat glands. These medications are usually taken orally and can have side effects such as vision problems, urination issues, digestive problems, and breathing difficulties.
  • Botulinum toxin injections: These injections block the nerves that stimulate sweat glands, reducing sweating. Injections are typically administered in the armpits, hands, or feet and can last for about 6 months.
  • Iontophoresis: It is mainly used for the hands and feet, less frequently for the armpits. It is used with a device that can be purchased over the counter. Sessions can also be performed by a physiotherapist, podiatrist, or equipped dermatologist. Learn more about iontophoresis devices.
  • miraDry: An aesthetic doctor or dermatologist uses a device (miraDry) to eliminate sweat glands in the armpits using waves. There are rare but serious side effects. Read my review of miraDry.
  • Thoracic sympathectomy or lumbar sympathectomy: This is a surgery performed under general anesthesia. The surgical team works on the nerve roots that innervate sweat glands. A common side effect is compensatory hyperhidrosis.

Treatments can also vary depending on the severity of hyperhidrosis, individual preferences, and potential risks associated with different treatments. Each treatment has its advantages and disadvantages!

I hope I have addressed your main questions about the phenomenon of excessive sweating with no reason.

By exploring the Hyperhidrosis Observatory website, you will find a wealth of information on this topic, as well as testimonials.

Do you have any comments or questions? Your comments are welcome 🙂 !

You may also like:


Endo et al., « Genome-Wide Association Study in Japanese Females Identifies Fifteen Novel Skin-Related Trait Associations ». 2018

Lear W, Kessler E, Solish N, et al. An epidemiological study of hyperhidrosis. Dermatol Surg 2007;33(s1):S69–75

SweatHelp : here

Pubmed: here

founder of Hyperhidrosis'Observatory

Written by Nelly Darbois

I founded this website in 2012. Since then, I’ve been providing information and positive support to people suffering from excessive sweating. I’m also a physical therapist and science writer, living in French Alps 🌞❄️.

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