Definition
What is Excessive sweating and body odor?
Sweating is a vital cooling system your body uses to regulate its temperature. There are two main types of sweat glands. Eccrine glands are spread throughout the body and are especially dense on the palms, soles, forehead and armpits; they produce an odorless sweat made of water and salt. Apocrine glands become active at puberty and are found in hairy areas like the armpits and groin; they produce a thicker secretion rich in fats and proteins. Underarm odor forms when bacteria break down precursor substances in this secretion.
Hyperhidrosis means sweating more than your body needs. The most common type is primary focal hyperhidrosis: it usually begins in adolescence or young adulthood, symmetrically affects specific areas like the armpits, palms, soles or face, generally stops during sleep, and often runs in families. Sweating over the whole body caused by another illness or a medication is called secondary hyperhidrosis and requires looking into the underlying cause. Bromhidrosis is the medical term for strong, unpleasant body odor; it most often affects the armpits and feet.
This topic matters especially for men. The composition of underarm secretions and the bacterial load are different in men; research has shown that the underarm odor of men who don't use deodorant is perceived as more intense than women's and that their bacterial load is higher. A soaked shirt, damp palms during a handshake or arms you can't raise in a meeting can directly affect your work life, confidence and relationships. Research shows that most people with hyperhidrosis are negatively affected at work, yet half have never mentioned it to a doctor. And there are many effective options, from simple product changes to clinical procedures.
Check yourself
How do you spot it?
- ✓Noticeable sweating of the armpits, palms or soles even without heat or exertion
- ✓Wet patches under the arms of your shirt or T-shirt that form quickly
- ✓Palms so wet you avoid shaking hands, holding paper or using your phone
- ✓Constantly wet socks that slip around inside your shoes
- ✓Strong underarm odor that comes back a few hours after showering
- ✓Yellow stains on white shirts and fading on colored T-shirts
- ✓A lingering smell in workout shirts that doesn't go away even after washing
- ✓Sweating that clearly increases with stress, meetings and social situations
- ✓Redness, chafing or fungus in areas that stay wet for a long time
Why it happens
Main causes
01
Overactive sweat glands (primary hyperhidrosis)
In primary focal hyperhidrosis, the sweat glands are structurally normal; the nervous system that stimulates them sends more signals than needed. There's usually a family history, and it begins in adolescence or young adulthood.
02
An underlying condition or medication (secondary hyperhidrosis)
Sweating over the whole body, especially with night sweats, that starts suddenly in adulthood may be linked to thyroid disease, diabetes, infections, certain medications and hormonal changes. In this case, a medical evaluation is essential.
03
The armpit microbiome
How strong the odor is depends largely on the makeup of the bacterial team in your armpits. In people where odor-producing bacteria dominate, much sharper odor can form even with the same amount of sweat.
04
Hair and hair follicles
Underarm hair provides a large surface that traps sweat and bacteria. Researchers emphasize that odor-causing bacteria live not only on the skin surface but also in sweat ducts and hair follicles.
05
Stress and emotional triggers
Stress, excitement and anxiety stimulate the sweat glands regardless of temperature. Stress sweat has a higher apocrine component, which is why it's usually smellier.
06
Diet, alcohol and smoking
Spicy foods, caffeine and alcohol can increase sweating; garlic, onions and some spices can change how your sweat smells. Smoking is also a noticeable part of body odor.
In daily life
Triggers that cause flare-ups
Medical approach
Treatment options
01
Clinical-strength antiperspirants
For mild to moderate underarm sweating, the first step is antiperspirants with aluminum salts, which temporarily plug the sweat duct openings. Your dermatologist may recommend stronger formulas. For the best effect, they're recommended to be applied to dry skin before bed; if irritation occurs, talk to your doctor.
02
Iontophoresis
For sweating of the palms and soles, the hands or feet are placed in a tray of water and exposed to a low-level electrical current. With regular sessions, sweating is seen to drop noticeably; the device can be used at a clinic or at home on your doctor's advice.
03
Botulinum toxin injections
For sweating of the armpits, palms and face, injections that temporarily block the nerve signals stimulating the sweat glands can be given after a dermatologist's evaluation. The effect usually lasts several months and needs to be repeated.
04
Oral medications
For widespread sweating or sweating that doesn't respond to other methods, your doctor may recommend oral medications that reduce sweating. Since they can have side effects like dry mouth, medical follow-up is needed.
05
Energy-based procedures and surgery
Energy-based procedures like microwave treatments that target the sweat glands in the armpits, as well as local surgical methods, can be used in selected patients. Surgery based on cutting nerves is considered a last resort because it carries a risk of compensatory sweating in other parts of the body.
06
Looking for secondary causes
For sweating that starts suddenly in adulthood, affects the whole body or comes with night sweats, your doctor will first look for thyroid-related, diabetes-related, infection-related and medication-related causes.
Did you know? · Excessive sweating and body odor
4.8% · In a US national sample of 8,160 people, the prevalence of excessive sweating (hyperhidrosis) was 4.8%; only half of those affected had discussed it with a healthcare professional.
Step by step
Care routine for Excessive sweating and body odor
5 steps
- 01
Shower and underarm cleansing
Wash your armpits with a gentle, low-pH cleanser; let the lather sit for about a minute, then rinse thoroughly.
- 02
Dry completely
Dry your armpits and between your toes thoroughly. Products applied to damp skin work less well and increase the risk of irritation.
- 03
Deodorant
In the morning, you can use a deodorant with probiotic or prebiotic ingredients that supports odor balance. If you use antiperspirant at night, you may not need to reapply it in the morning.
- 04
The right fabric
Choose cotton or fabrics that wick sweat away quickly; if your underarm wetness is noticeable, wearing a thin cotton undershirt under your shirt reduces stains.
- 05
For your feet
If your feet sweat, wear moisture-wicking socks, rotate your shoes and carry a spare pair of socks.
Caution
What to avoid, and when to see a doctor?
Avoid these
- ✕Trying to cover up odor with heavy fragrance or cologne
- ✕Applying products to wet or damp armpits
- ✕Using antiperspirant right after shaving
- ✕Washing your armpits many times a day with harsh antibacterial soap
- ✕Long workouts in polyester shirts followed by putting off your shower
- ✕Wearing the same shoes every day
- ✕Ignoring night sweats and sudden, widespread sweating
- ✕Never talking to a doctor about sweating because it feels 'embarrassing'
See a dermatologist
- →If sweating affects your daily work, handshakes or social life
- →If you have night sweats that wake you up and soak your sheets
- →If sweating started suddenly in adulthood and all over your body
- →If sweating comes with weight loss, fever, a racing heart or fatigue
- →If you sweat on only one side of your body
- →If over-the-counter antiperspirants aren't working
- →If your odor has suddenly changed and doesn't improve with hygiene
Common misconceptions
Myth or fact?
✕Common belief
Sweat smells bad, and people who sweat a lot are dirty.
✓Fact
Sweat is actually odorless. The smell is produced by certain bacteria in the armpit breaking down substances in sweat. Excessive sweating is a medical condition related to the nervous system that stimulates the sweat glands, not to hygiene.
✕Common belief
Deodorant and antiperspirant are the same thing.
✓Fact
Deodorant targets odor; it affects bacterial balance or masks the smell. Antiperspirant reduces the amount of sweat by temporarily plugging the sweat ducts. For excessive sweating, antiperspirant takes the lead; for odor, deodorant does. You can also use both together.
✕Common belief
If I drink more water, I'll sweat more, so I should drink less.
✓Fact
Restricting water doesn't reduce sweating; it just dehydrates your body and disrupts heat balance. The answer to excessive sweating isn't cutting back on water but the right product and, if needed, a doctor's help.
Popular searches
Most asked about Excessive sweating and body odor
Your questions
Frequently asked questions
01Why do I smell again a few hours after showering?+
A shower washes away sweat and some of the bacteria on the surface, but the bacterial team living in the hair follicles and sweat ducts of your armpits comes back quickly. As new sweat arrives, the odor forms again. Drying your armpits thoroughly, keeping hair short, choosing the right fabric and using a deodorant that supports microbiome balance can slow down this cycle.
02Why should I apply antiperspirant at night?+
At night, the sweat glands are less active and your skin is dry. This lets the antiperspirant's active ingredient settle into the sweat ducts better and work throughout the next day. Your morning shower doesn't wash away much of this effect.
03Why do my workout shirts smell even after washing?+
On synthetic fabrics like polyester, some bacteria grow more easily than on cotton, and odor compounds can build up inside the fibers. Washing your workout shirt right away instead of leaving it in your bag, turning it inside out, washing at a higher temperature if possible and choosing cotton blends when needed all help.
04My palms sweat all the time. Can this be treated?+
Yes. Palm sweating is a common form of primary hyperhidrosis. Your dermatologist may consider options like strong antiperspirants, iontophoresis, botulinum toxin injections or oral medications. Most men get noticeable relief with the right method.
05Does removing underarm hair reduce odor?+
Trimming or removing hair can lessen odor because it reduces the surface that traps sweat and bacteria. But skin becomes more sensitive after shaving; applying antiperspirant or alcohol-based products right after shaving can cause burning. Keeping hair short with a trimmer is enough for most men and is a less irritating option.
06When can excessive sweating be a sign of another condition?+
If sweating started suddenly in adulthood, affects your whole body, wakes you up at night or comes with weight loss, fever, a racing heart and fatigue, there may be an underlying cause. In that case, you should see a doctor to check for thyroid-related, diabetes-related, infection-related and medication-related causes.
Scientific basis
Sources
- 01Hyperhidrosis: an update on prevalence and severity in the United States.
Doolittle J, Walker P, Mills T, Thurston J · Arch Dermatol Res · 2016 · doi:10.1007/s00403-016-1697-9
In a national sample of 8,160 people, the prevalence of excessive sweating was 4.8%; only 51% of those affected had discussed it with a healthcare professional.
- 02The etiology, diagnosis, and management of hyperhidrosis: A comprehensive review: Etiology and clinical work-up.
Nawrocki S, Cha J · J Am Acad Dermatol · 2019 · doi:10.1016/j.jaad.2018.12.071
A comprehensive review covering the causes of primary and secondary hyperhidrosis, how to tell them apart and the steps of clinical evaluation.
- 03Primary focal hyperhidrosis: disease characteristics and functional impairment.
Hamm H, Naumann MK, Kowalski JW, Kütt S, Kozma C, Teale C · Dermatology · 2006 · doi:10.1159/000092285
Of 345 hyperhidrosis patients, 63% reported being negatively affected at work, and more than half reported moderate to severe limitations in relationships and social settings.
- 04Mapping axillary microbiota responsible for body odours using a culture-independent approach.
Troccaz M, Gaïa N, Beccucci S, Schrenzel J, Cayeux I, et al. · Microbiome · 2015 · doi:10.1186/s40168-014-0064-3
People who didn't use antiperspirant had on average 50 times more bacteria in their armpits; men's underarm odor was more intense and their bacterial load was higher.
- 05The specific biochemistry of human axilla odour formation viewed in an evolutionary context.
Natsch A, Emter R · Philos Trans R Soc Lond B Biol Sci · 2020 · doi:10.1098/rstb.2019.0269
A review summarizing at the molecular level that underarm odor forms when odorless precursor substances secreted by the body are broken down by enzymes of armpit bacteria.
- 06Characterization of Staphylococcus and Corynebacterium clusters in the human axillary region.
Callewaert C, Kerckhof FM, Granitsiotis MS, Van Gele M, Van de Wiele T, et al. · PLoS One · 2013 · doi:10.1371/journal.pone.0070538
A study showing that the armpit microbiome is made up of bacterial clusters that differ from person to person and that this composition is linked to odor formation.
- 07Microbial odor profile of polyester and cotton clothes after a fitness session.
Callewaert C, De Maeseneire E, Kerckhof FM, Verliefde A, Van de Wiele T, Boon N · Appl Environ Microbiol · 2014 · doi:10.1128/AEM.01422-14
After an intense cycling session, polyester T-shirts were shown to smell stronger and more unpleasant than cotton ones, with different bacteria growing on the synthetic fabric.
- 08The effect of habitual and experimental antiperspirant and deodorant product use on the armpit microbiome.
Urban J, Fergus DJ, Savage AM, Ehlers M, Menninger HL, et al. · PeerJ · 2016 · doi:10.7717/peerj.1605
Deodorant and antiperspirant use was shown to strongly change the density and composition of armpit bacteria; when the product was stopped, bacterial density increased.
- 09Towards a bacterial treatment for armpit malodour.
Callewaert C, Lambert J, Van de Wiele T · Exp Dermatol · 2017 · doi:10.1111/exd.13259
An opinion paper suggesting that replacing an odor-producing armpit microbiome with a non-odor-producing one, applying probiotics and selective steering with prebiotics could be part of future odor management.
