Does obesity cause excessive sweating?

The evidence shows an association, not proof of cause. A study of 2.77 million adolescents found hyperhidrosis was diagnosed more often as body mass index rose, and adults with obesity sweat more during exercise. Much of this is explained by more heat to lose and more insulating fat, rather than damage to the sweat glands.

How much more common is hyperhidrosis with obesity?

In the largest study, hyperhidrosis affected about 2.9% of adolescent men with obesity versus 1.5% of normal-weight men, and 1.6% versus 1.1% of women. The adjusted odds were roughly 1.4 times higher for men with obesity and about 1.2 times higher for women.

Why do heavier people sweat more?

A larger body produces and stores more heat, especially during activity, so more evaporative cooling is needed. Subcutaneous fat also insulates the body and slows dry heat loss, which shifts more of the cooling load onto sweating.

Is the extra sweating a sign of a sweat-gland problem?

Not necessarily. In exercise, higher sweat rates in people with obesity largely reflect body size and heat load. In one study, self-reported sweating was higher in overweight and obese participants, but measured sweating outside the face was similar to normal-weight participants.

Is this page medical advice?

No. It is a summary of verified figures from published sources and makes no recommendation about weight. Only a clinician can evaluate an individual's sweating.

Research

Obesity and Sweating: What the Evidence Shows

People with a higher body mass often report sweating more, and the research supports a real association. A nationwide study of 2.77 million adolescents found that hyperhidrosis was more common as body mass index rose, and exercise studies show that adults with obesity tend to have higher sweat rates during prolonged activity. The physiology is largely mechanical: more body mass and insulating fat mean more heat to shed and slower dry heat loss, so the body relies more on evaporative sweating. This page summarizes what the peer-reviewed literature reports. It is educational only and is not a diagnosis or medical advice.

By the Sweat Explained Editorial Team · Published 2026-07-20 · Last reviewed 2026-07-20 · Educational information, not medical advice.

Key statistics at a glance

2.9% vs 1.5%
hyperhidrosis prevalence in adolescents with obesity versus normal weight (men) in a study of 2.77 million
Astman 2019 (JAAD)
aOR ~1.4
adjusted odds of hyperhidrosis for adolescent men with obesity versus normal weight (~1.2 for women)
Astman 2019 (JAAD)
higher sweat rate
obese adults had significantly higher sweat rates than lean adults during prolonged moderate exercise
Eijsvogels 2011 (Int J Obes)
~93%
of hyperhidrosis is primary and focal; obesity is one factor linked to reported sweating, not a proven cause of primary hyperhidrosis
Nawrocki & Cha 2019 (JAAD)

What the largest study found

The strongest population evidence comes from a nationwide, cross-sectional study of 2.77 million Israeli adolescents screened before military service, in which hyperhidrosis was diagnosed by a dermatologist (Astman et al., JAAD 2019). Hyperhidrosis was more common in participants with obesity than in those of normal weight: about 2.9% versus 1.5% in men and 1.6% versus 1.1% in women.

After adjustment, the odds of hyperhidrosis rose with body mass index. The adjusted odds ratio was roughly 1.4 for men with obesity and about 1.2 for women, compared with normal-weight peers, and the risk increased incrementally with each unit of body mass index. The authors were careful to note that the study could not identify whether the sweating was primary or secondary, so it establishes an association rather than a cause.

The physiology of why more mass means more sweat

Sweating exists to cool the body by evaporation. Two mechanical facts make heavier bodies sweat more. First, a larger body generates and stores more heat, especially during activity, so more evaporative cooling is needed. Second, subcutaneous fat is an insulator that slows heat loss by conduction and convection (dry routes), which shifts the burden toward evaporative sweating as the compensatory route.

This plays out during exercise. In a study of 93 participants walking 30 to 50 km, adults with obesity had significantly higher sweat rates and higher fluid intake than lean participants, and tended toward higher peak core temperature (Eijsvogels et al., 2011). The higher sweat rate is best understood as an appropriate response to a larger heat load and greater insulation, not as a defect of the sweat glands themselves.

Factors linking higher body mass to more sweating

Several mechanisms are described in the literature, spanning mechanics, metabolism, and measurement.

Why higher body mass is associated with more sweating
Factor	How it increases sweating	Support
Greater heat production	More tissue and effort during activity generate more metabolic heat to dissipate	Eijsvogels 2011
Insulating fat layer	Fat slows dry heat loss, so evaporative sweating carries more of the load	Dobosz 2019 (discussion)
Larger surface area and mass	More heat storage and a higher absolute cooling requirement	Eijsvogels 2011
Higher reported prevalence	Hyperhidrosis diagnosed more often as body mass index rises	Astman 2019
Perception vs measurement	Overweight people report more sweating, though objective sweat rates outside the face may be similar	Dobosz 2019

Mechanisms overlap. Much of the difference in exercise sweat rate is explained by body size and heat load rather than a change in how individual sweat glands work.

Reported sweating versus measured sweating

Not every method agrees. A study of medical students compared self-reported sweating with gravimetric (weighed) measurement and found that overweight and obese participants rated their sweating as more severe, yet objective measurements outside the facial area were similar to those of normal-weight participants (Dobosz et al., 2019). Only facial sweating was measurably higher.

This gap between perception and measurement matters for interpretation. Higher reported prevalence of hyperhidrosis with higher body mass is consistent and real, but part of the association reflects how sweating is experienced and reported, and much of the exercise difference reflects body size and heat load. The evidence does not show that obesity damages sweat glands or that it causes primary hyperhidrosis.

Where obesity fits among causes of sweating

About 93% of hyperhidrosis is primary and focal, meaning it is not explained by another condition (Nawrocki & Cha, 2019). Obesity is best viewed as one contributing factor associated with more sweating and a higher chance of a hyperhidrosis diagnosis, alongside the mechanical realities of carrying more mass. It is not, on the current evidence, a proven cause of primary hyperhidrosis.

It is also worth separating routine heat-related sweating from sweating that is a red flag. Generalized sweating that begins in adulthood, continues through sleep, or comes with fever, unintentional weight loss, or other systemic symptoms is a reason to see a clinician regardless of body weight, because it can point to a secondary cause.

What this means in plain terms

Higher body mass is genuinely associated with more sweating. In the largest study, hyperhidrosis was diagnosed more often as body mass index rose, and in exercise studies adults with obesity sweat more. The most consistent explanation is physiological and mechanical: more heat to lose and a thicker insulating layer push the body toward evaporative cooling. Some of the association also reflects how sweating is perceived and reported.

This page describes an association reported in the literature and the physiology behind it. It does not make claims about weight change or offer any recommendation, and it is not a diagnosis or medical advice. Anyone concerned about excessive sweating can discuss it with a clinician.

Methodology and limitations

This page draws on Astman et al. 2019 (J Am Acad Dermatol, nationwide study of 2.77 million adolescents), Eijsvogels et al. 2011 (Int J Obes 35:1404-1412, prolonged-exercise study of 93 participants), Dobosz et al. 2019 (Adv Dermatol Allergol, subjective versus objective sweating in students), and Nawrocki & Cha 2019 (JAAD comprehensive review) for the primary-versus-secondary framing. Each figure (2.9% vs 1.5% in men, adjusted odds ratios ~1.4 and ~1.2, higher sweat rate during exercise, and ~93% primary hyperhidrosis) was traced to those sources.

Limitations: the 2.77-million study is cross-sectional, so it shows association not causation, and it could not classify hyperhidrosis as primary or secondary. The adolescent cohort may not generalize to older adults. Exercise sweat-rate differences are strongly influenced by body size and heat load, and gravimetric studies suggest reported and measured sweating can diverge. Nothing here is a diagnosis or medical advice, and this page makes no recommendation about weight.

Frequently asked questions

Does obesity cause excessive sweating?: The evidence shows an association, not proof of cause. A study of 2.77 million adolescents found hyperhidrosis was diagnosed more often as body mass index rose, and adults with obesity sweat more during exercise. Much of this is explained by more heat to lose and more insulating fat, rather than damage to the sweat glands.
How much more common is hyperhidrosis with obesity?: In the largest study, hyperhidrosis affected about 2.9% of adolescent men with obesity versus 1.5% of normal-weight men, and 1.6% versus 1.1% of women. The adjusted odds were roughly 1.4 times higher for men with obesity and about 1.2 times higher for women.
Why do heavier people sweat more?: A larger body produces and stores more heat, especially during activity, so more evaporative cooling is needed. Subcutaneous fat also insulates the body and slows dry heat loss, which shifts more of the cooling load onto sweating.
Is the extra sweating a sign of a sweat-gland problem?: Not necessarily. In exercise, higher sweat rates in people with obesity largely reflect body size and heat load. In one study, self-reported sweating was higher in overweight and obese participants, but measured sweating outside the face was similar to normal-weight participants.
When should sweating be checked by a clinician?: Regardless of body weight, generalized sweating that begins in adulthood, continues during sleep, or comes with fever, unintentional weight loss, or other systemic symptoms is worth discussing with a clinician, because it can indicate a secondary cause.
Is this page medical advice?: No. It is a summary of verified figures from published sources and makes no recommendation about weight. Only a clinician can evaluate an individual's sweating.

Sources

Primary peer-reviewed studies and official sources first, then reviews and institutional framing (secondary).

Astman N, Friedberg I, Wikström JD, et al. The association between obesity and hyperhidrosis: a nationwide, cross-sectional study of 2.77 million Israeli adolescents. J Am Acad Dermatol. 2019 (published online 21 Jan 2019). Hyperhidrosis more common with higher BMI; obese vs normal-weight men 2.9% vs 1.5%; adjusted odds ratio ~1.4 (men) and ~1.2 (women). PubMed
Eijsvogels TMH, Veltmeijer MTW, Schreuder THA, Poelkens F, Thijssen DHJ, Hopman MTE. The impact of obesity on physiological responses during prolonged exercise. Int J Obes (Lond). 2011;35(11):1404-1412. Obese participants had significantly higher sweat rates and fluid intake than lean participants during prolonged walking. PubMed
Dobosz Ł, Stefaniak T, Halman J, et al. Differences in subjective and objective evaluation of hyperhidrosis. Study among medical students. Postepy Dermatol Alergol (Adv Dermatol Allergol). 2019;36. Overweight and obese participants reported more sweating, but gravimetric sweating outside the face was similar to normal-weight participants. (secondary) Full text
Nawrocki S, Cha J. The etiology, diagnosis, and management of hyperhidrosis: a comprehensive review. Part I: etiology and clinical work-up. J Am Acad Dermatol. 2019;81(3):657-666. About 93% of hyperhidrosis is primary and focal; secondary hyperhidrosis is usually generalized. (secondary) PubMed
Moraites E, Vaughn OA, Hill S. Incidence and prevalence of hyperhidrosis. Dermatol Clin. 2014;32(4):457-465. Background on primary versus secondary and focal versus generalized hyperhidrosis. (secondary) PubMed

How to cite this page

Sweat Explained. Obesity and Sweating: What the Evidence Shows. Published 2026-07-20; last reviewed 2026-07-20. Available at: https://sweatexplained.com/research/obesity-and-sweating

Please cite the original studies for the underlying figures. Journalists are welcome to link to this page; the charts are original renderings of the cited data.