People with excessive sweating (hyperhidrosis) sweat profusely, and some sweat almost constantly.
Excessive sweating usually has no clear cause but is sometimes caused by infections, metabolic problems, or cancer.
Skin that is always wet can become red and inflamed or pale, wrinkled, and cracked and can develop a foul odor.
The diagnosis is made by a doctor's evaluation and sometimes tests.
Although people with a fever or those exposed to very warm environments sweat, people with excessive sweating tend to sweat even without these circumstances.
(See also Introduction to Sweating Disorders.)
Focal excessive sweating
Excessive sweating may affect the entire surface of the skin but is often limited to certain parts of the body (called focal excessive sweating). The parts most often affected are the palms of the hands, soles of the feet, forehead, and armpits. Sweating in these areas is usually caused by anxiety, excitement, anger, or fear. Although such sweating is a normal response, people with excessive sweating sweat profusely and under conditions that do not cause sweating in most people.
Some people also sweat around the lips, nose, and forehead when they eat hot, spicy foods (called gustatory sweating). Gustatory sweating is normal, but certain disorders can increase such sweating, such as diabetes that affects the nerves, shingles affecting the face, brain disorders, certain disorders affecting the autonomic nervous system in the neck, and certain injuries affecting the nerves to the salivary gland in front of the ear (the parotid gland).
Generalized excessive sweating
Excessive sweating that affects most of the body is called generalized excessive sweating. Usually, no specific cause is found. However, a number of disorders can cause generalized excessive sweating, including heat exposure and fevers.
Some Causes of Excessive Sweating
Type | Examples |
|---|---|
Cancer* | Lymphoma, leukemia, carcinoid tumors, some tumors of the adrenal glands |
Medications and substances | Antidepressants, aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs), some medications for diabetes, caffeine, and theophylline Withdrawal from opioids |
Hormonal (endocrine) disorders | An overactive thyroid gland (hyperthyroidism), low blood sugar levels (hypoglycemia), diabetes that affects the nerves, and certain pituitary gland disorders or use of medications that affect pituitary gland function |
Infections* | Tuberculosis, heart infection (endocarditis), and severe fungal infections affecting the entire body |
Nervous system disorders | Injuries (such as Frey syndrome†), dysfunction of the autonomic nervous system, and some brain disorders |
Other‡ | Pregnancy Anxiety, excitement, anger, or fear Fever Heat exposure Sweating around the lips and mouth after eating hot, spicy foods (called gustatory sweating) Certain surgeries Unknown |
* These types primarily cause night sweats. | |
† Frey syndrome is a nervous system disorder that results from damage (caused by, for example, surgery or shingles) to the nerves that control the sweat glands for the salivary glands in the front of the ear. As a result, people sweat and have facial flushing while they eat. | |
‡ Some degree of sweating caused by these conditions can be normal. | |
Symptoms of Excessive Sweating
Sometimes the area becomes red and inflamed. The area may emit a foul odor (bromhidrosis) due to the breakdown of sweat by bacteria and yeasts that normally live on the skin. Severe, chronic wetness can make the affected area pale, wrinkled, and cracked. Clothing may also become soaked with sweat.
People who sweat excessively are frequently anxious about their condition, and it may lead to social withdrawal. This anxiety may make the sweating worse.
Diagnosis of Excessive Sweating
A doctor's evaluation
Sometimes tests
Doctors usually base the diagnosis of excessive sweating on the person's history and a physical examination.
Occasionally, they may apply substances to the skin that make small amounts of sweat visible.
Doctors may also do blood tests and hormone screenings to detect other disorders.
Treatment of Excessive Sweating
Aluminum chloride solution applied to the skin
Anticholinergic medications taken by mouth or applied to the skin
Clonidine taken by mouth
Botulinum toxin type A injections
Medical devices
Surgical procedures
Sometimes hyperhidrosis can lead to body odor (bromhidrosis), which can be treated by cleansing twice a day with soap and water or, if this is ineffective, with other measures used to treat bromhidrosis.
Aluminum chloride solution
At night, the person first dries the sweaty area and then applies the solution. In the morning, the person washes the area. At the start of treatment, the person must apply the solution several times until the sweating is controlled. Then an application once or twice a week is sufficient to maintain relief for as long as necessary.
The solution should not be applied to inflamed, broken, wet, or recently shaved skin.
Sometimes doctors also give the person an anticholinergic medication to take by mouth (see below), which can cause anticholinergic side effects.
Anticholinergic medications
are anticholinergic medications that can be taken by mouth. Sometimes doctors have people with excessive sweating take these medications before applying aluminum chloride solution to prevent sweat from washing the solution away. However, these medications can cause side effects called anticholinergic effects. Anticholinergic effects can include blurred vision, dry mouth, and difficulty urinating. These side effects may lead people to stop using anticholinergic medications (see sidebar Anticholinergic: What Does It Mean?).
is another anticholinergic medication that is used to reduce excessive armpit sweating in people 9 years of age and older. Once a day, people take only one towelette that is premoistened with this medication and use it to wipe each armpit once. Glycopyrronium tosylate can cause anticholinergic effects.
are other anticholinergic medications that may be given as gels or other formulations that can be applied to the skin to treat excessive sweating.
Clonidine
Botulinum toxin type A
Botulinum toxin type A can be injected directly into the armpits, palms, or forehead to inactivate the nerves that trigger sweating. It prevents sweating for about 5 months depending on the dose.
These injections are effective but can cause muscle weakness and headache, are painful, and are expensive. Also, treatment must be repeated 2 to 3 times per year.
Because botulinum toxin type A can be used only for excessively sweaty armpits, its use at other sites may not be covered by insurance.
Botulinum toxin type A also can be applied in a cream. This may be a treatment option for some people.
Medical devices
Tap-water iontophoresis, a process in which a weak electrical current is applied to the sweaty areas (typically palms or soles) for 10 to 20 minutes, is sometimes used. This routine is done daily for 1 week and then repeated weekly or about twice per month.
Although the treatments are usually effective, the process is time-consuming and somewhat cumbersome, and some people get tired of the routine.
A special microwave-based device uses heat to permanently destroy sweat glands. People may benefit from 2 treatments at least 3 months apart. Results last for a few months.
Laser devices have been used to treat excessive sweating by damaging the skin structures that cause sweating. A laser also may be used to enhance treatment with botulinum toxin A solution.
Surgery
Surgical procedures to control severe sweating may be tried if other treatments are not effective.
Excessive sweating limited to the armpits is sometimes treated by removing the sweat glands via surgery or liposuction.
Excessive sweating limited to the palms can be treated by a procedure called endoscopic transthoracic sympathectomy, in which the nerves leading to the sweat glands (these nerves are located near the spinal column in the chest) are cut. However, sympathectomy can cause permanent complications such as phantom sweating (a sensation of sweating, but no sweat exists), compensatory sweating (increased sweating in untreated parts of the body), gustatory sweating, nerve pain, and Horner syndrome. Compensatory sweating is most common after endoscopic transthoracic sympathectomy, develops in up to 80% of people, and can be disabling and far worse than the original problem.
