We all sweat, but underarm wetness at the wrong time can still be embarrassing. According to research conducted by the International Hyperhidrosis Society, 33% of U.S. adults feel like they produce too much underarm sweat. Knowing what causes you to sweat can help you figure out how to fix it.
Types of Sweat Glands
There are two primary kinds of sweat glands, eccrine glands and apocrine glands.
The eccrine glands are located all over the body and produce a watery sweat that cools your body down when it gets hot – like during exercise or hot weather. Sweat from your eccrine glands contains natural moisturizers and antimicrobial properties that can keep your skin healthy and potentially protect against infection, according to research published in the journal Temperature.
The apocrine glands are located at the base of hair follicles of body hair on the scalp, armpits and groin. When the apocrine glands sweat, they create a milky fluid that contains fat. When this sweat combines with the natural bacteria on skin, it creates the stinky “body odor” smell you may associate with sweating. The apocrine glands typically only sweat in response to stress.
“People sweat for many reasons, some of it is healthy bodily function and some of it can be a symptom of something else that’s happening in the body,” Says Tim Arakawa, MD, PhD, from Samaritan Endocrinology in Corvallis. “If you notice a change in the way you sweat, or that you sweat consistently in certain situations, it can help you determine how to manage this potentially embarrassing condition.”
Main Causes of Sweat
Sweating while exercising is a healthy and normal response. If you are new to exercise, you may notice that it takes longer to work up a sweat. Dr. Arakawa reports that as you become more physically fit, you will begin to sweat more easily as the body becomes more efficient at cooling you down.
The fix: Don’t try to reduce the amount you sweat during exercise since it’s an important function of your body. Instead, choose clothing labeled “moisture-wicking,” “quick-drying” or “performance” for exercise or if you know you’ll be out in the heat. These garments are usually made of polyester or nylon which don’t absorb much moisture, and are designed with a special weave to lift sweat off your skin and take it to the surface of the garment where it quickly evaporates.
Cotton, on the other hand, soaks up moisture and holds onto it. It’s a great trait in a towel, but doesn’t work well for exercise gear. A long workout in a damp cotton t-shirt can leave you feeling clammy and uncomfortable and make it harder for your body to regulate your temperature, says Dr. Arakawa.
For those who prefer natural fabrics, merino wool is a good choice with moisture wicking ability. There are plenty of workout-minded products made with merino, from socks and sports bras to shirts and tights. It’s a no-brainer as a base layer for cold-weather exercise, but some people use merino gear year-round as traditional workout clothing.
Hormone changes often trigger excessive sweating. This can happen during puberty, and in pregnancy or menopause for women.
According to Dr. Arakawa, the apocrine sweat glands become active during puberty which is why teenagers often have a distinct smell. Hot flashes and night sweats during pregnancy and menopause are more commonly the watery, exercise-type sweat.
The fix: Wear breathable fabrics like cotton and linen to help keep you cool when it’s hot, but if you know you’re going to sweat regardless of the weather, choose moisture-wicking fabric instead. If night sweats are causing you to wake up uncomfortable and needing to change your clothes or sheets, look into moisture-wicking pajamas and bedding.
While cotton and linen sheets are good all-around choices for warmer weather, these natural fibers absorb moisture and keep it close to your body so you wake up feeling soaked and uncomfortable. Moisture-wicking or quick-drying night gear can be harder to find so your best bet might be specialty online retailers.
For teenagers, daily cleansing, a combination antiperspirant and deodorant, and washing clothes after every wear can go a long way toward addressing body odor.
Stressful events like giving a presentation or a near miss on the freeway can stimulate the apocrine sweat that leads to body odor. After the event is over, you’ll stop sweating, but this fatty sweat interacts with the bacteria on your skin and can leave you smelling less than fresh until your next shower.
The fix: On days you know you might have stress, be sure and wear a combination antiperspirant and deodorant to minimize body odor and reduce wetness. Wiping down afterward with unscented baby wipes can help if you can’t shower right away. If you suffer from generalized anxiety or chronic stress that leave you sweaty on a regular basis, take steps to help get it under control.
Food, Drink & Medication
Spicy food, meat, caffeine and alcohol can increase your metabolism and make you start sweating. Some prescription medications can also make you sweatier.
The fix: Pay attention to what you’re consuming that makes you sweaty and try to avoid those items if it’s important to stay dry (like on a date), but Dr. Arakawa notes that sweating in response to food or drink isn’t harmful. If you’ve noticed a bothersome increase in the amount you sweat since starting a new medicine, talk to your doctor about it.
Hyperhidrosis is a disorder characterized by greater-than-normal sweating that’s not related to heat or exercise. Prescription-strength antiperspirant can usually control the condition, but other options like Botox or surgery may be helpful in some cases.
Sweating can also be a symptom of a more serious disorder like hyperthyroidism, diabetes or low blood sugar, so if you’ve noticed a change in the amount you sweat it’s a good idea to talk to your doctor.
Using a combination antiperspirant deodorant is the first place to start managing your sweat. An antiperspirant works by plugging your sweat glands so you produce less sweat, while deodorant combats any odor. You can use antiperspirant deodorant under your arms, on your feet and even along your hairline if you become uncomfortably sweaty in those areas. Cornstarch or powder also work well to absorb excess moisture.
Aluminum is the active ingredient in antiperspirant that keeps you from sweating, so check the ingredients in your antiperspirant and choose a variety with 15-20% aluminum for maximum protection. It sounds counterintuitive, but Dr. Arakawa recommends applying antiperspirant to clean underarms before bed rather than in the morning. This allows the product time to work before you start sweating the next day. Don’t worry – showering the next morning won’t wash it off.
You can try drug store antiperspirants labeled “clinical” or “extra strength,” but if you still struggle with underarm wetness talk to your doctor about a prescription. Dr. Arakawa notes that a prescription antiperspirant called Drysol is commonly used and is typically very effective at significantly reducing underarm sweat.
Help for Stinky Sweat
To prevent the buildup of odor-causing sweat on your skin, make sure you wash with soap regularly and after any sort of sweaty event. Since your scalp, groin and armpits are the main culprits of body odor, do a thorough scrub of those areas, not just a rinse with water. You may need to try a different brand of antiperspirant deodorant if your current choice isn’t doing the trick.
If you notice your shoes are stinky even when you’re not wearing them, make sure they dry out completely before the next time you wear them. You should also wash your feet thoroughly every day in the shower – don’t count on the leftover suds swishing around the floor to do the job. Shoes that are made of natural fibers like cotton or leather will be more breathable and keep your feet cooler. Use antiperspirant on your feet and powder or cornstarch to soak up excess moisture, and change your socks midday if you need to.
Is Sweat a Detox?
Dr. Arakawa notes there is not good evidence that sweat can “detox” your body of heavy metals, alcohol or other toxins. While sweating during exercise or taking a sauna can be good for general health, Dr. Arakawa cautions against excessive sweating as a form of detox.
“In general, sweating is normal but a change in your sweat can mean a change in your health,” says Dr. Arakawa. “Talk to your doctor if you are sweating more or less than usual since this could be a symptom of a more serious condition.”
Get more information about sweat in our health library.