Sweating – everything you need to know

What is sweat (perspiration)?

Sweat is a fluid made almost entirely of water, with trace amounts of other substances (e.g. salt and ammonia), secreted by sweat glands located throughout the body.

What types of sweat glands do we have?

There are two types of sweat glands: apocrine and eccrine glands. They are located in different regions of the body and produce different types of sweat.

What are the main characteristics of sweat glands?

Eccrine glands secrete a clear, odorless fluid that plays a role in regulating body temperature. Apocrine glands are found around hair follicles and produce a different type of secretion related to body odor.

What characterizes apocrine sweat?

Apocrine sweat is produced by apocrine glands in areas rich in hair follicles, such as the scalp, underarms and groin. Apocrine glands open into hair follicles and lead to the skin surface. They secrete a concentrated, oily sweat that contributes to body odor.

What characterizes eccrine sweat?

Eccrine glands are found over the entire body surface. They are most dense on the palms, soles and forehead. Eccrine sweat is essentially an odorless, dilute salt water. These sweat glands are responsible for regulating body temperature.

What triggers sweating?

Common triggers of sweating include physical activity, stress, high temperature, illness and eating.

Why do we sweat?

The body uses sweating to regulate temperature, keeping you cool and comfortable and preventing overheating.

How does sweating cool the body?

The process is called evaporative cooling. When sweat reaches the skin surface and evaporates, it cools the body.

Why is sweating important?

It is a very important bodily function that regulates body temperature and prevents overheating. Those who do not sweat (anhidrosis / hypohidrosis) are at risk of severe, life-threatening complications such as heat stroke.

How is sweating activated?

When the body starts to warm up, the nervous system activates eccrine sweat glands throughout the body, which secrete sweat (a clear, odorless fluid) to cool down. Once the sweat reaches the skin surface and evaporates, it produces a cooling effect.

Why do I sweat when I eat?

Certain foods can activate sweat glands or put them into a higher level of activity. Coffee and alcohol can cause this.
During the digestion of heavy foods, the body works hard to convert food into energy. The more difficult a food is to digest, the more it can stimulate sweating.
Very hot, spicy and strongly seasoned foods can also trigger sweating during a meal.
If you sweat constantly while eating (or even just thinking about food), you should consider the condition known as gustatory hyperhidrosis.

Why do I sweat while sleeping?

People sweat during sleep as well. If it is mild, some may not even notice it!
Night sweats are characterized by waking up feeling drenched in sweat regardless of the ambient temperature. It is a very common symptom with many possible causes. Most often it indicates another disease or a side effect of medication.

Does sweating help with weight loss?

Sweating by itself does not lead to weight loss and you do not burn more calories simply by sweating a lot. Sweating can help you lose body water. That water weight is immediately recoverable by drinking a few glasses of water.

Does sweating mean I'm burning a lot of fat?

No, sweating does not reduce fat. Although the water lost through sweat can temporarily show as measurable weight loss (during a long workout you may lose even 1–2 kg of water), that is not fat and will be regained with rehydration after exercise.

Does more sweat mean a more effective workout?

Not necessarily. The amount of sweat during exercise depends on many factors, including ambient temperature, your fitness level, age and weight.

What can sweating indicate?

Excessive sweating can also indicate an abnormal condition. It can be a symptom of a disease or a side effect of medication.
If your sweating pattern has changed recently, consult a doctor to rule out possible illnesses. Many medications are known to increase sweating.
If there is no disease or medication cause, excessive sweating may be due to primary hyperhidrosis.

Does sweat cause pimples (acne)?

Not at all! Sweat alone does not cause pimples. In fact, it may help prevent them because sweat contains antibacterial proteins that kill bacteria commonly responsible for acne.

Does sweat have an odor?

Sweat itself is odorless. The smell associated with sweat only appears when skin bacteria start breaking it down. That releases sulfurous odors. In severe cases this is called bromhidrosis.

Do I sweat out toxins?

No. Sweat is almost entirely water, so sweating is not a form of detoxification. The amount of toxins in sweat is negligible because the liver and kidneys—not the sweat glands—are responsible for removing toxins.

How much does an average person sweat per day?

There are 2–4 million sweat glands in the human body, which can produce up to 10–14 liters of sweat per day (in adults) under extreme conditions.
The amount of sweat depends on many factors, primarily ambient temperature, but also age, sex, body weight and fitness level.
An average adult with a sedentary job loses about 450 ml of sweat per day (in most cases unnoticed), while an athlete can lose up to 1200 ml per hour during training.

Do I sweat too much?

Everyone sweats, but the amount of sweat is usually normal. If sweating interferes with your daily activities or you sweat for no reason, you may have hyperhidrosis. This condition is characterized by excessive, abnormal sweating (sweating that exceeds what is necessary for body temperature regulation).

When do we talk about increased sweating?

There is no definite answer, but if sweating affects your daily life, you should seek treatment or talk to a healthcare professional.
The human body is roughly 73–75% water, and losing just 1% of it can cause dehydration.

What types of sweating disorders are there?

Anhidrosis or hypohidrosis: the patient is unable to sweat and this can be life-threatening in hot conditions because the body cannot lower its temperature and may overheat.
Bromhidrosis: characterized by very unpleasant body odor.
Chromhidrosis: a very rare condition in which sweat is not colorless but may be various colors.
Hyperhidrosis: a very common condition characterized by excessive (pathologically strong) sweating.

Why does my body sweat for no reason?

If uncontrollable, excessive sweating is not caused by disease or medication side effects, it is likely primary hyperhidrosis.

What is compensatory sweating?

Compensatory sweating is a common side effect of surgeries for hyperhidrosis. Severing a nerve in the treated area completely stops sweating there, which the body compensates for by increasing sweating elsewhere. Although sweating stops in the original area, it may appear in other places.

What can I do about sweating?

Abnormal sweating (hyperhidrosis) is mostly a treatable condition.

Read this article: Hyperhidrosis, i.e. abnormal sweating 

If abnormal sweating affects the palms, soles or underarms, you are fortunate because there is a very effective treatment called tap-water iontophoresis. In my experience, more than 95% of those who receive the treatment report a favorable effect, meaning the method helps.

If large areas such as your scalp, neck, back, chest, abdomen or thighs are affected, this method is currently not applicable (because there is no device that can treat such a large area at once).