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.
Treatment may include aluminum chloride antiperspirants, glycopyrronium tosylate towelettes, anticholinergic drugs, clonidine, tap-water iontophoresis, botulinum toxin, a microwave-based device, and sometimes surgery.
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 Introduction to Sweating Disorders Sweat is made by sweat glands in the skin and carried to the skin’s surface by ducts. As sweat wets the skin and evaporates, it helps keep the body cool. Thus, people normally sweat more when... read more .)
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 Complications of Diabetes Mellitus People with diabetes mellitus have many serious long-term complications that affect many areas of the body, particularly the blood vessels, nerves, eyes, and kidneys. (See also Diabetes Mellitus... read more 
that affects the nerves, shingles Shingles Shingles is a painful skin rash caused by a viral infection that results from reactivation of the varicella-zoster virus, the virus that causes chickenpox. What causes the virus to reactive... read more 
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.
Symptoms of Excessive Sweating
Sometimes the area becomes red and inflamed. The area may emit a foul odor (bromhidrosis Body Odor Body odor that is excessive or abnormal (bromhidrosis) is the result of the breakdown of sweat by bacteria and yeasts that normally live on the skin. (See also Introduction to Sweating Disorders... read more ) 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
Glycopyrronium tosylate towelettes
Anticholinergic drugs taken by mouth
Clonidine taken by mouth
Tap-water iontophoresis
Botulinum toxin type A injections
Microwave-based device
Surgical procedures
A prescription-strength aluminum chloride solution applied to the skin is stronger than a commercial antiperspirant and is often needed to treat excessive sweating, particularly of the palms, soles, armpits, or genital area. 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 drug to take by mouth (see below), which can cause anticholinergic side effects.
Cloth towelettes premoistened with glycopyrronium tosylate can be used to reduce excessive sweating under the arms in people 9 years of age and older. Once a day, people take only one towelette and use it to wipe each underarm once. Glycopyrronium tosylate can cause anticholinergic effects (see below).
Anticholinergic drugs taken by mouth may be given to some people. Sometimes doctors give the anticholinergic drugs glycopyrrolate or oxybutynin to take before applying aluminum chloride solution to prevent sweat from washing the aluminum chloride away. However, these drugs 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 drugs ( see Anticholinergic: What Does It Mean? Anticholinergic: What Does It Mean? 
).
Clonidine taken by mouth may help some people. It is used most often to treat high blood pressure, but it also decreases sweating by blocking the effects of the sympathetic division, the part of the autonomic nervous system that can rapidly respond to stress.
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.
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 the U.S. Food and Drug Administration (FDA) has approved botulinum toxin type A only for excessively sweaty armpits, its use at other sites may not be covered by insurance.
A special microwave-based device uses thermal (heat) energy to create heat and permanently destroy sweat glands. People may benefit from two treatments at least 3 months apart.
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 near the spinal column in the chest leading to the sweat glands are cut. However, surgery 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 Horner Syndrome Horner syndrome affects one side of the face, causing the eyelid to droop, the pupil to become small (constricted), and sweating to decrease. The cause is disruption of the nerve fibers that... read more 
. Compensatory hyperhidrosis 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.
Sometimes hyperhidrosis can lead to body odor (bromhidrosis Body Odor Body odor that is excessive or abnormal (bromhidrosis) is the result of the breakdown of sweat by bacteria and yeasts that normally live on the skin. (See also Introduction to Sweating Disorders... read more ), which can be treated by cleansing twice daily with soap and water or, if this is ineffective, with other measures used to treat bromhidrosis.
