Sweating

Related Terms

Anhidrosis, antiperspirant, apocrine glands, deodorant, eccrine glands, endoscopic thoracic sympathectomy, excessive sweating, fever, flushing, heat rash, heatstroke, hot flashes, hyperhidrosis, menopause, night sweats, perspire, sweat glands, sweating.

Background

It is normal for people to perspire, or sweat, when they are warm or experiencing emotional stress. Sweating helps maintain proper body temperature by keeping the body cool. When people are under stress, sweat glands contract, which pushes sweat to the skin surface. People may lose several quarts of fluid in perspiration.
There are two types of sweat glands on the skin: the eccrine glands and the apocrine glands. About 2-5 million eccrine glands are found on almost all areas of skin. When the body's temperature increases, the nervous system signals the eccrine glands to secrete sweat onto the skin. The sweat is primarily made up of salt and water. When the sweat evaporates, it cools the body.
Apocrine glands are present in areas that contain many hair follicles, including the armpits, groin, and scalp. Apocrine glands secrete a fatty sweat that contains pheromones. Unlike eccrine glands, which respond to heat, apocrine glands respond to emotional stress and sexual activity. When the sweat touches the skin, bacteria on the skin start to break it down. When the bacteria break down apocrine sweat, it can cause an offensive odor.
When someone sweats more than the average, the condition is called hyperhidrosis. Sweating too much may be embarrassing if it is visible through the clothing or if it causes an offensive odor. Excessive sweating may also be a sign of a more serious condition, such as an infection (like the flu), low blood sugar levels, or certain types of cancer. In addition, some medications, menopause, and low testosterone levels may also lead to increased sweating.
When people sweat too little or not all, the condition is called anhidrosis. Certain types of cancer, severe burns, and extreme dehydration are just some of the possible causes of anhidrosis. This condition ranges from mild to life threatening. If anhidrosis is localized to one part of the body, the condition is generally not a major health concern. However, if many of the sweat glands are involved it can be dangerous because sweating is an important function that prevents the body from overheating. If the body is unable to sweat enough, the person's body temperature may become too hot, and it can potentially lead to organ damage or failure.
Treatment to reduce or increase sweating varies depending on the severity of the underlying cause.

Signs and symptoms

General: It is normal for sweat to occur in response to heat, exercise, anxiety, nervousness, or stress.
Excessive sweating: Individuals who experience excessive sweating may sweat even when they are not exercising or exposed to emotional stress. Some people may inherit a tendency to sweat heavily, particularly on the palms of the hands and soles of the feet. This is not a serious health problem, although it may be embarrassing for some people.
Some people may experience hot flashes. This occurs when a person suddenly feels extremely warm for no apparent reason and begins to sweat profusely.
Some people may experience night sweats during sleep. Patients may wake up covered in sweat in the middle of the night and experience chills.
Sweating may also occur in combination with other symptoms. For instance, if a person has an infection, he/she may have a fever, chills, and feel nauseous in addition to sweating. When people have low blood sugar levels, they may experience increased sweating in addition to weakness, hunger, shaking, and lightheadedness.
Decreased or absent sweating: People with decreased or absent sweating do not sweat enough in response to heat, exercise, or emotional stress. The severity of decreased sweating depends on the underlying cause.

Diagnosis

Patients should visit their doctors if they suddenly start to sweat more or less than usual or experience night sweats for no apparent reason. Patients should also visit their doctors if they experience sweating that is accompanied by a fever and chills.
Since sweating problems are generally signs of an underlying condition, many different tests may be performed to determine the cause. For instance, blood tests may be performed to determine if the patient has low blood sugar levels, low testosterone levels (in men), low estrogen levels (in women), or high thyroxine levels. These conditions may lead to increased sweating.
In some cases, a doctor may be able to make a diagnosis after a detailed medical history and physical examination. For instance, a doctor may determine that medication is causing increased sweating if the patient is taking drugs that are known to increase sweating.

Complications

Fungal infections: Individuals who sweat excessively have an increased risk of developing many types of fungal infections, including those that affect the nails, feet, and genitals. This is because fungi prefer warm, moist environments.
Patients who sweat excessively are prone to a fungal nail infection called onychomycosis. Patients may develop discolored, thick, brittle, or crumbly fingernails or toenails, which may be painful. The nails may become distorted in shape, flat, or dull.
Patients who sweat a lot are also prone to athlete's foot, a fungal infection of the foot that causes itching, stinging, and burning anywhere on the feet. Symptoms are usually most noticeable in between the toes. Patients may also develop itchy blisters, cracked or peeling skin, dry skin, or toenails that are thick, crumbly, discolored, or pulling away from the nail bed.
Jock itch, a fungal infection that affects the skin of the inner thighs, buttocks, and genitals, is also common among patients who sweat a lot. Symptoms typically include a red, itchy or burning rash that may cause the skin to become flaky.
Bacterial infections: Individuals who sweat excessively are prone to bacterial infections, especially between the toes or near hair follicles.
Warts: People who sweat a lot have an increased risk of developing warts, which are skin growths caused by the human papillomavirus (HPV).
Heat rash: Excessive sweating, especially in hot, humid weather, may lead to heat rash. The excessive sweat damages the cells on the skin's surface and blocks the sweat glands. As a result, the sweat is trapped under the skin causing tiny red bumps to form, usually on the upper back, chest, or arms. As the bumps burst and sweat is released, patients may feel a prickly or stinging sensation.
Heatstroke: Heatstroke may cause some cases of anhidrosis. However, it may also develop as a complication of anhidrosis that affects many parts of the body. If a patient has severe anhidrosis, the body is prone to becoming overheated. This is a serious life-threatening condition because the body's internal organs start to shut down in response to extreme temperatures. Patients who experience decreased or absent sweating, rapid heartbeat, rapid and shallow breathing, increased blood pressure, irritability, confusion, unconsciousness, and fainting, should be taken to the nearest hospital.
Social and emotional effects: Patients who sweat excessively may feel embarrassed, especially if the sweat is visible through the clothing or it causes an offensive odor. For instance, if the palms of the hands are excessively sweaty, the hands may feel clammy, and the person may feel uncomfortable shaking hands with others.

Treatment

General: Treatment to reduce or increase sweating varies depending on the severity of the underlying cause.
Lifestyle changes: Bathing or showering every day reduces the amount of bacteria on the skin, which may help reduce body odor.
After bathing, it is important to thoroughly dry the feet. People should also go barefoot whenever possible to help dry the feet. This helps prevent fungal infections that affect the nails or feet. Over-the-counter food powders are available to help absorb sweat. Wearing shoes and socks made of natural materials, such as cotton and leather, may help reduce sweating because they allow for better ventilation. Cotton socks may help absorb sweat from the feet. Athletic socks that wick away sweat may also be beneficial during exercise. Socks should be changed once or twice daily. Patients who have very sweaty feet should try to avoid wearing the same pair of shoes two days in a row. This gives the shoes enough time to dry.
Wearing clothing made from natural fibers, such as cotton, wool, or silk, may help reduce sweating. During exercise, fabrics that wick sweat away may also be beneficial.
Individuals who sweat excessively in response to emotional stress may benefit from relaxation techniques such as yoga or meditation. These therapies may help people learn how to control emotions that trigger sweating.
Avoiding or reducing the consumption of spicy foods or hot beverages that contain caffeine or alcohol (such as coffee, tea, or beer), may help prevent increased sweating.
Antiperspirant or deodorant: Some patients who sweat excessively may only need to use over-the-counter antiperspirant or deodorant. Antiperspirants block the sweat ducts under the arms, preventing sweat from reaching the skin. They are typically applied in the morning or after showering. People who experience night sweats can reapply antiperspirant before bed. Patients with more severe sweating problems may need prescription-strength antiperspirants. Although it has been suggested that the aluminum salts in antiperspirants may lead to breast cancer, there is a lack of scientific evidence to support this claim. Antiperspirants may irritate the skin or cause the skin to become red, swollen, and itchy.
Deodorants are used to reduce or eliminate odor, but they do not reduce sweating. Deodorants are made with alcohol, which helps prevent bacteria from breaking down sweat and causing odor. Some also have fragrances to help mask the smell of body odor. Deodorants are commonly used under the arms and on the hands and feet. Many antiperspirants are also deodorants. Deodorants are generally less irritating for most people.
Iontophoresis: A procedure called iontophoresis may be used to treat excessive sweating. During the procedure, a battery-powered device delivers a low current of electricity to the area of the body that sweats a lot, such as the palms of the hands or under the arms. Iontophoresis is usually repeated every other day for 5-10 days or until sweating is reduced. Once the patient's sweating is reduced to a comfortable level, they receive fewer treatments that range from once a week to once a month. Iontophoresis can be performed at a doctor's office or a doctor can write a prescription for a home-use iontophoresis machine. Even though this technique is safe and painless, it may not be any more effective than over-the-counter antiperspirant.
Botulinum toxin (Botox?): Injections with botulinum toxin (Botox?) have been used to treat severe hyperhidrosis. The injections paralyze the nerves that signal sweating. Several injections may be necessary. The results typically last about 1-4 months.
Side effects include pain at the injection site, flu-like symptoms, headache, and upset stomach. Injections in the face may also cause the eyelids to temporarily appear droopy. Avoid if pregnant or breastfeeding.
Anticholinergic drugs: Patients who experience increased sweating throughout the body may benefit from anticholinergic drugs such as glycopyrrolate (Robinul?, or Forte?). These drugs block a chemical messenger (called acetylcholine) that stimulates the sweat glands. These medications usually start to work in about two weeks.
Side effects may include constipation, blurred vision, dry mouth, loss of taste, dizziness, confusion, and decreased urinary output.
Acetaminophen: Patients who experience increased sweating as a result of a fever typically take acetaminophen (such as Tylenol?). Acetaminophen should not be taken for more than three days when treating a fever. Patients should visit their healthcare providers if a fever lasts for more than three days because it may be a sign of a serious health condition, such as an infection.
Hormone replacement therapy: Hormone replacement therapy may help reduce sweating associated with menopause or low levels of testosterone in males (hypogonadism). Hormone therapy with estrogen may help alleviate menopause symptoms, including flushing and night sweats. However, according to research, patients who receive estrogen have an increased risk of stroke. Patients should talk to their healthcare providers to determine the potential health benefits and risks associated with hormone therapy. Males with hypogonadism typically receive testosterone injections to reduce symptoms.
Radioactive iodine: Patients with overactive thyroids typically take radioactive iodine by mouth. The thyroid gland absorbs this medication, which stimulates the gland to shrink. Symptoms, including increased sweating, usually start to improve within 3-6 months of treatment. However, many patients develop hypothyroidism as a result of radioactive iodine treatment. If hypothyroidism develops, patients need to take thyroxine (Euthyrox?, Levothroid?, Levoxyl?, Synthroid?, or Unithroid?) for life.
Side effects may include sore throat and mild nausea. In rare cases, the salivary glands may swell.
Surgery: Surgery may be beneficial for some patients with excessive sweating. For instance, if patients experience severe sweating that only occurs under the arms, some or all of the sweat glands may be removed.
Another surgical procedure, called endoscopic thoracic sympathectomy, involves cutting the nerves that signal the sweat glands to perspire. However, after the surgery, sweating may increase in other parts of the body.

Integrative therapies

Unclear or conflicting scientific evidence:
Belladonna: There is currently a lack of reliable scientific evidence available for the effectiveness of belladonna for treatment of excessive perspiration. More research is needed in this area.
Avoid if allergic to belladonna or plants of the Solanaceae(nightshade) family (bell peppers, potatoes, eggplants). Avoid with a history of heart disease, high blood pressure, heart attack, abnormal heartbeat (arrhythmia), congestive heart failure, stomach ulcer, constipation, stomach acid reflux (serious heartburn), hiatal hernia, gastrointestinal disease, ileostomy, colostomy, fever, bowel obstruction, benign prostatic hypertrophy, urinary retention, glaucoma (narrow angle), psychotic illness, Sj?gren's syndrome, dry mouth (xerostomia or salivary gland disorders), neuromuscular disorders such as myasthenia gravis, or Down's syndrome. Avoid if pregnant or breastfeeding.
Traditional or theoretical uses lacking sufficient evidence:
Aconite: The aconite plant grows in rocky areas. It is often found in the mountainous woodlands of many parts of Europe, especially France, Austria, Germany, and Denmark. Aconite has been suggested as a possible antiperspirant. However, until scientific studies are performed, it remains unknown if aconite is safe or effective for treatment of excessive perspiration.
Aconite is highly toxic and is not safe for human consumption. Avoid with heart disease, irregular heartbeat, hemodynamic instability (abnormal blood flow), and gastrointestinal disorders (such as ulcers, reflux esophagitis, ulcerative colitis, spastic colitis, or diverticulosis). Use cautiously with diabetes or suicidal tendencies. Avoid if younger than 18 years old due to a lack of safety evidence. Avoid if pregnant or breastfeeding.
Ginger: The underground stems (called rhizomes) and above ground stems of ginger have been used in Chinese, Japanese, and Indian medicine for hundreds of years. It has been suggested, but not scientifically proven, that ginger taken by mouth may help treat patients with excessive perspiration. Scientific research is needed in order to determine if this treatment is safe and effective.
Avoid if allergic to ginger or other members of the Zingiberaceaefamily (such as red ginger, shell ginger, or green cardamom). Stop two weeks before and immediately after surgery/dental/diagnostic procedures with bleeding risks. Avoid with a history of irregular heartbeat (arrhythmia). Use cautiously with a history of ulcers, acid reflux, heart conditions, inflammatory bowel disease, blocked intestines, bleeding disorders, or gallstones. Use cautiously if taking anticoagulants. Use cautiously if driving or operating machinery. Use cautiously if pregnant or breastfeeding.
Ginseng: For more than 2,000 years, the roots of this slow-growing plant have been valued in Chinese medicine. Traditionally, ginseng has been used to help reduce sweating. However, it remains unknown if this treatment is effective for the treatment of excessive perspiration because scientific studies are currently lacking in this area.
Avoid if allergic to ginseng or other plants in the Araliaceae family. Avoid with bleeding disorders, leukemia, or liver disorders. Avoid if taking anticoagulants or anti-platelet drugs. Avoid consuming ginseng in combination with licorice if pregnant or postpartum. Use cautiously with gastrointestinal disorders, high blood pressure, hormone-dependent conditions (such as breast cancer or prostate cancer), sleep disorders, attention deficit hyperactivity disorders (ADHD), irregular heartbeat, heart disease, diabetes, joint or muscle disorders (such as arthritis or fibromyalgia), eye disorders, or psychological disorders. Use cautiously if taking ACE inhibitors, lipid-lower agents, anti-cancer drugs, cytotoxic drugs, stimulants (including caffeine), diuretics, glucocorticoids, HIV protease inhibitors, monoamine oxidase inhibitors (MAOIs), morphine, mitomycin C, sodium channel blockers, nifedipine, agents that increase photosensitivity, or drugs that are broken down by the liver. Use cautiously if undergoing chemotherapy or radiation therapy.
Lemongrass: Lemongrass oil is an essential oil used in deodorants, herbal teas, skin care products, fragrances, and insect repellents. It is also commonly used during aromatherapy. Until scientific studies are conducted, it remains unknown if lemongrass is an effective treatment for excessive perspiration.
Avoid if allergic to lemongrass, its constituents, or any members of the Poaceae family. Use cautiously if taking diabetic or heart medications or drugs that are broken down by the liver. Use cautiously with liver conditions. Avoid if pregnant or breastfeeding.
Meditation: Individuals who sweat excessively in response to emotional stress may benefit from relaxation techniques such as meditation. This therapy may help people learn how to control emotions that trigger sweating. However, studies testing the effectiveness of meditation for treatment of excessive perspiration are lacking.
Use cautiously with underlying mental illnesses. People with psychiatric disorders should consult with their primary mental healthcare professionals before starting a program of meditation, and they should explore how meditation may or may not fit in with their current treatment plans. Avoid with risk of seizures. The practice of meditation should not delay the time to diagnosis or treatment with more proven techniques or therapies, and it should not be used as the sole approach to illnesses.
Valerian: Valerian is an herb native to Europe and Asia. Today the herb grows in most parts of the world. Theoretically, valerian may help reduce sweating. However, until research is conducted, it remains unknown if valerian is an effective antiperspirant.
Use cautiously if allergic to valerian or other members of the Valerianaceaefamily. Use cautiously with livers disorders. Use cautiously before surgery. Avoid if driving or operating heavy machinery, as it may cause drowsiness. Avoid if pregnant or breastfeeding.
Yoga: People who sweat excessively in response to emotional stress may benefit from relaxation techniques, such as yoga. This therapy may help people learn how to control emotions that trigger sweating. However, studies testing the effectiveness of yoga for treatment of excessive perspiration are currently lacking.
Yoga is generally considered to be safe in healthy individuals when practiced appropriately. Avoid some inverted poses with disc disease of the spine, fragile or atherosclerotic neck arteries, extremely high or low blood pressure, glaucoma, detachment of the retina, ear problems, severe osteoporosis, cervical spondylitis, or if at risk for blood clots. Certain yoga breathing techniques should be avoided with heart or lung disease. Use cautiously with a history of psychotic disorders. Yoga techniques are believed to be safe during pregnancy and breastfeeding when practiced under the guidance of expert instruction. However, poses that put pressure on the uterus, such as abdominal twists, should be avoided in pregnancy.

Prevention

Drink plenty of water to prevent dehydration and heatstroke. It is also important to drink plenty of liquids after sweating to replace lost fluids.
Extreme exercise, especially in hot weather, increases the risk of experiencing dehydration or heatstroke. Therefore, people are encouraged to choose activities that fit their levels of strength and endurance.
Individuals with diabetes or hypoglycemia should check their blood sugar levels regularly. Low blood sugar levels may cause increased sweating, among other symptoms.
Avoiding or reducing the consumption of spicy foods, hot beverages, or drinks that contain caffeine or alcohol (such as coffee, tea, or beer) may help prevent increased sweating.
Antiperspirant may help reduce the amount of sweating under the arms. Deodorant may help prevent or reduce the odor associated with sweating.

Author information

This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Bibliography

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Endocrine and Metabolic Diseases Information Service. .
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No authors listed. Treatments for excessive armpit sweating. Drug Ther Bull. 2005 Oct;43(10):77-80.
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Taylor RD. Common causes of night sweats in various populations. Am Fam Physician. 2003 Oct 1;68(7):1264.

Causes

General: It is normal for people to sweat when they are warm or experiencing emotional stress. Sweating helps maintain proper body temperature by keeping the body cool. When people are under stress, sweat glands contract, which pushes sweat to the skin surface.
There are many reasons why individuals may sweat too much or not enough. Below are some of the most common causes. However, some people may sweat more than others for no apparent reason.
Fevers: A common cause of increased sweating is fevers. A fever occurs when the body temperature is higher than normal. In general, the normal human body temperature should be around 98.6 degrees Fahrenheit. Fevers typically occur in response to infections. Patients often experience excessive sweating once the body temperature starts to return to normal. This is how the body cools itself down.
Foods and beverages: Certain foods and beverages may cause increased sweating. For instance, eating spicy foods or drinking hot beverages or drinks that contain caffeine or alcohol (such as coffee, tea, or beer) may increase sweating.
Heart attack: Severe sweating may also occur during a heart attack, when the heart becomes damaged due to a loss of blood supply. In addition to increased sweating, patients may also experience pain or pressure in the chest that radiates to the left shoulder, arm, or back. A heart attack is a medical emergency. Anyone who experiences these symptoms should seek immediate medical treatment.
Heredity: Excessive sweating, particularly of the palms of the hands and soles of the feet, can be inherited, or passed down from parents to their children. This is not considered a serious health problem, although it may be embarrassing for some people.
Low blood sugar (hypoglycemia): When individuals have low blood sugar levels, they may experience increased sweating in addition to weakness, hunger, shaking, and lightheadedness. This condition, called hypoglycemia, is common among diabetics.
Low testosterone levels (hypogonadism): Men who have hypogonadism, a condition that causes men to have low levels of the male hormone testosterone, may experience hot flashes. However, it is normal for older men (40-55 years of age) to have hot flashes when they experience a natural decline in testosterone levels.
Medications: Certain medications, including certain antipsychotic medications, morphine, high doses of the thyroid hormone thyroxine, and pain relievers (such as aspirin or acetaminophen), may increase sweating.
Menopause: A common symptom of menopause is hot flashes, which occur when a woman suddenly starts sweating because she feels extremely warm. Some women may also experience night sweats during sleep followed by chills. These symptoms occur because menopausal women have low estrogen levels. Symptoms usually last for less than one year after the last menstrual period.
Overactive thyroid (hyperthyroidism): Excessive sweating may also be caused by hyperthyroidism, which occurs when the thyroid gland produces too much of the hormone thyroxine. This hormone helps control growth and the rate at which the body uses energy (metabolism). Excessive sweating is a common symptom of hyperthyroidism along with sudden weight loss and irregular heartbeat.
Certain types of cancer: Some types of cancer, such as leukemia or lymphoma, may cause people to sweat more or less than normal.
Burns: Second-degree burns or third-degree burns, which affect several layers of skin, may destroy sweat glands. As a result, the affected area of skin will not perspire, even after the wounds are healed. This is typically a mild form of anhidrosis because in many cases, only a localized part of the body is affected.
Extreme dehydration: Extreme dehydration may lead to decreased sweating. This is because the body does not have enough fluid to produce sweat. Although dehydration can be easily reversed by drinking fluids, it is potentially life threatening. If left untreated, dehydration can cause heatstroke, kidney failure, brain swelling, seizures, shock, coma, and death. Signs of dehydration include dry skin, thirst, less frequent urination, light-headedness, and dark-colored urine.
Heatstroke: Heatstroke, a condition that occurs when the body temperature is extremely high, may also lead to decreased or absent sweating. Most cases of heatstroke are caused by overexertion, particularly in warm or hot climates. Other risk factors for heatstroke include dehydration, consumption of alcohol, heart disease, and certain medications. Heatstroke is a life-threatening condition because the body's internal organs start to shut down. Patients who experience decreased or absent sweating, rapid heartbeat, rapid and shallow breathing, increased blood pressure, irritability, confusion, unconsciousness, and fainting should be taken to the nearest hospital.
Horner's syndrome: A rare condition, called Horner's syndrome, may cause decreased or absent sweating. Horner's syndrome occurs when the sympathetic nerves of the face and eye become damaged. These nerves, which regulate sweating and circulation, may become damaged as a result of a tumor, stroke, or injury to the carotid artery. As a result, patients experience decreased sweating on the affected side of the face, as well as droopy eyelids and decreased pupil size.