How can you tell if your sweating is excessive?

Perspiration is a normal and essential physiological phenomenon. It enables the body to maintain a stable core temperature, around 37°C, by dissipating heat produced by metabolism or accumulated as a result of environmental conditions.

Aside from periods of sustained physical exertion or high heat, the body produces on average about one litre of sweat per day.

For this reason, there is no simple, universal threshold that makes it possible to state from what quantity sweating becomes “abnormal”. In practice, the term hyperhidrosis is used when sweat is produced in an amount greater than the actual requirements for thermoregulation and when it becomes a source of everyday discomfort. In other words, sweating is considered excessive not only because of its intensity, but also because of its functional, social or emotional impact. Several concrete signs may suggest hyperhidrosis:

• Hands that become so moist that they interfere with simple movements, such as holding a steering wheel, using a keyboard, handling a pen or shaking someone’s hand.

• Clothing that becomes rapidly wet, without particular effort or excessive heat.

• The need to shower or change clothes several times within the same day.

• Discomfort associated with a smell of perspiration.

This troublesome feature is ultimately one of the best indicators of excessive sweating. When perspiration impairs quality of life, one may wonder whether this is a case of hyperhidrosis.

To better understand whether sweating is excessive, it is also possible to observe how it is distributed over the body. In most cases, hyperhidrosis is described as localised, meaning that it affects certain specific areas, most often the armpits, the palms of the hands, the soles of the feet or the face. Conversely, more rarely, sweating can be generalised and involve the entire body. This form accounts for around 10% of cases and can appear at any age.

It should also be noted that a distinction is made between primary and secondary hyperhidrosis.

Primary hyperhidrosis is the most common form. It usually corresponds to localised sweating, without any clearly identified medical cause. It is thought to be linked to an overactivity of the sympathetic nervous system, which stimulates the sweat glands excessively, even when there is no real physiological need. Certain factors can trigger or worsen episodes, such as stress, intense emotions, heat, physical exertion, the consumption of alcohol or spicy foods. A genetic predisposition is also suggested, with a significant proportion of patients having a family history.

Conversely, secondary hyperhidrosis is linked to an identifiable cause. It is often generalised, but may also be localised in certain cases. It can be associated with various situations or medical conditions, such as the menopause, being overweight, anxiety disorders, the use of certain medications, or diseases such as hyperthyroidism, certain infections, cancers or Parkinson’s disease.

Several strategies can help to reduce sweating. If these are not sufficient, do not hesitate to consult a doctor so that they can help you find a solution.

• BREWER J. D. & al. Management of hyperhidrosis. Clinical, Cosmetic and Investigational Dermatology (2014).

• CHA J. & al. The etiology, diagnosis, and management of hyperhidrosis: A comprehensive review. Journal of the American Academy of Dermatology (2019).

• JEMEC G. & al. How to diagnose and measure primary hyperhidrosis: A systematic review of the literature. Clinical Autonomic Research (2021).