When we say "no sweat!" we mean "no problem!" But the truth is, no sweat would actually be a very big problem. Sweating regulates our body temperature and keeps us from overheating; it's a bodily function with much-needed benefits. (Perspiration is also frequently thought to be the body's method of "flushing out" toxins, but this is now considered to be a misconception, according to WebMD.)
We have up to four million sweat glands on our bodies, and a healthy adult sweats up to ten liters a day. However, it is possible to sweat too much (called hyperhidrosis) or too little (known as anhidrosis)—and both can be red flags alerting to you certain concerning conditions. Read on to find out what your sweat could be trying to tell you about your health.
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Your thyroid is out of whack.
Hyperthyroidism—the medical term for an overactive thyroid gland—can be the culprit behind your dripping brow. "Hyperthyroidism may cause sensitivity to heat and excessive sweating, where a person suffering from hypothyroidism may struggle to keep warm at all," according to Penn Medicine. (Hypothyroidism is the term for an underactive thyroid.)
"When the body's thyroid is working properly, its cells will produce 65 percent energy and 35 percent heat," they explain. "However, those with a thyroid condition will either be producing too much or not enough thyroxine." These hormonal changes can alter your body's perspiration production, causing excess heat and decreased energy, or the other way around.
Other symptoms of hyperthyroidism may include fatigue, weight fluctuations, and swelling at the base of the neck where the thyroid is located.
Your nervous system is malfunctioning.
Hardly ever breaking a sweat may sound appealing, but can, in fact, be very extremely harmful. "Sweating helps remove heat from your body so you can cool down," according to the Cleveland Clinic. "If you can't sweat, your body overheats, which can be dangerous and even life-threatening."
While some people are born with anhidrosis, it may also be a symptom of a condition affecting the nervous system. "Blood pressure, pulse, sweating and the digestive process are regulated by a part of the nervous system that is often affected by Lewy body dementia," according to the Mayo Clinic, which notes that anhidrosis can also be a sign of "Parkinson's disease, stroke and spinal cord disease."
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You're having a heart attack.
"Sweating more than usual—especially if you aren't exercising or being active—could be an early warning sign of heart problems," says Healthline. "Pumping blood through clogged arteries takes more effort from your heart, so your body sweats more to try to keep your body temperature down during the extra exertion."
Commonly known heart attack symptoms include shortness of breath and pain in the chest, shoulder, and/or arm. But sudden, profuse sweating can also be a warning sign of a heart attack—and interestingly, it is a symptom that can lead people to seek immediate medical attention: Catherine Ryan, PhD, RN, and project coordinator of medical-surgical nursing in the department of nursing at the University of Illinois at Chicago, told WebMD that heart attack patients who sweat are more likely to seek treatment sooner.
You need to get checked for diabetes.
Increased perspiration can be a sign of diabetes. "Research shows that up to 84 percent of people with diabetes experience sweating when they're hypoglycemic, with the most common sweat area being behind the neck," explains Verywell Health. When hypoglycemia occurs, "adrenaline is produced in response to declining blood sugar levels, which results in the narrowing of blood vessels and the activation of sweat glands," their experts write.
In addition to sudden, excessive sweating, other symptoms of diabetes may include a frequent urge to urinate, unexplained weight loss, numb or tingling hands and feet, and persistent, extreme thirst.
You may have cancer.
It might seem like an unlikely cancer symptom, but night sweats can actually indicate several different types of the disease. Healthline cites the following six kinds of cancer where excessive sweating can be a possible symptom: carcinoid tumors, leukemia, lymphoma, bone cancer, liver cancer, and mesothelioma.
"It's unclear why some types of cancer cause night sweats," Healthline says. Sweating may be caused by hormone changes, fever, or the body trying to fight the cancer. In some cases, night sweats are not a symptom of the onset of cancer, but rather due to "treatments such as chemotherapy, drugs that alter hormones, and morphine."
If waking up with soaked sheets is your only symptom, however, there's no need to panic. David Beatty, MRCGP, a general practitioner with more 30 years of experience, told Best Life that night sweats would probably not be the only symptom if cancer was the cause: "I don't ever recall seeing a patient who presented with just night sweats who had cancer and hadn't already been diagnosed," he says.
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