What Makes You Sweat

Reviewed by Louise Chang, MD on August 11, 2010
Source: 2010 WebMD


Heat and Humidity

When the temperature rises, your sweat glands (some 2.6 million of them) spring into action, producing perspiration. Sweating is your body’s natural way of keeping you cool. Some sweat evaporates from your skin, taking heat with it. The rest runs down your face and body. You feel hotter when it's humid out because the already saturated air leaves less room for the sweat to evaporate off your body.

Getting Mad Can Cause Sweating

When you get angry, your body reaches its boiling point, releasing stress hormones that increase your heart rate and blood pressure and raise your body temperature, which can lead to sweating. Anger is a healthy emotion once in a while, but when you regularly lose your temper, it could signal a problem.

Exercise Makes You Sweat

Breaking a sweat is one way to tell that you're getting a good workout. Because you lose fluid when you sweat -- especially when it's hot -- you need to stay hydrated. Remember to hydrate before you work out in addition to while you’re working out and after you are done. This will help with body temperature and performance, too.

Being Under Pressure

Anyone who's missed a big work deadline or choked up in front of an audience knows how stress, anxiety, and embarrassment can make you sweat. Emotional stress specifically activates the sweat glands in the palms of your hands and soles of your feet, which is why it can be embarrassing to shake hands when you're nervous.

Fevers

When you're sick, your brain raises your body’s thermostat a few degrees. You’ll feel cold and have chills as your body raises its temperature to make it a less welcoming place for germs. When your fever breaks and your thermostat resets itself back to about 98.6 degrees, you’ll feel hot and start to sweat. The sweat helps to cool you off back to a normal temperature.

Feeling Sick Can Cause Sweating

Being sick can make you sweat, and not just because you have a fever. Sweating can be a symptom of angina -- heart-related chest pain -- and a heart attack. Infections, diabetes, and an overactive thyroid gland all can make you sweat. Some diseases, like cancer and HIV, can cause night sweats. If you're sweating a lot and are concerned, see your doctor.

Coffee

That morning cup of Joe will do more than wake you up -- it can also make you sweat. Coffee increases perspiration in two ways. First, caffeine stimulates the central nervous system, activating sweat glands (the more caffeine you drink, the more you sweat). Second, the heat from the drink itself can make your body feel hot enough to sweat.

Spicy Foods Can Cause Sweating

When you bite into a double-jalapeno burrito, why does it feel like a four-alarm fire has just erupted in your mouth? Spicy foods fool your body into thinking it's hot by stimulating the same nerve receptors that respond to heat. That's why a plate of hot wings or bowl of spicy soup can make your tongue sizzle and your face break out in a sweat.

Menopause and Hot Flashes

During menopause, plunging estrogen levels play tricks on the hypothalamus -- the body's temperature gauge. No matter how frigid it is outside, a hot flash will make your body think you're in the middle of a heat wave. In a desperate attempt to shed excess heat, the blood vessels in your skin dilate and your sweat glands go into overdrive, leaving you feeling flushed, sweaty, and yearning for a cold shower.

Too Much Alcohol

You can tell right away when someone's been throwing back a few too many drinks. He’s wobbly on his feet, slurring his speech, and his face is flushed and sweaty. The sweatiness is due to an alcohol effect called vasodilation -- widening of the blood vessels in the skin.

Smoking

Here's another reason to stamp out that cigarette: Smoking can make you sweat. Nicotine causes your body to release the chemical acetylcholine, which stimulates the sweat glands. It also raises heart rate and blood pressure and body temperature. Nicotine withdrawal also causes excess perspiration, but if you can sweat it out long enough to kick the habit, you'll lower your risk for cancer, emphysema, and dozens of other deadly diseases.

Sweating Can Be a Medicine Side Effect

Though they're meant to make us feel better, some medications can cause their own symptoms. Sweating may be a side effect of several drugs, including antidepressants, nonsteroidal anti-inflammatory drugs (NSAIDs), blood pressure medications, cancer treatments, and some diabetes drugs. If your drugs are making you too sweaty, talk to your doctor about changing your dose or switching to another drug.


Love Can Make You Sweat

You might feel like you've lost your head, but falling in love actually starts in your brain, with a rush of adrenaline-like "love chemicals." These are responsible for the racing heart, sweaty palms, and other telltale physical signs that you're smitten.

Pregnancy

Hormones surging through your body during pregnancy and an increased metabolic rate can make you hotter than usual and make your sweat glands more active. Be sure to drink enough fluid during those nine months to keep you and your baby hydrated. Once your baby arrives, you'll keep sweating more than usual for a few weeks as your body sheds the extra fluid it accumulated during pregnancy.

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