Hyperhidrosis is a medical condition in which a person sweats excessively and unpredictably. People with hyperhidrosis may sweat even when the temperature is cool or when they are at rest.

Sweating helps the body stay cool. In most cases, it is perfectly natural. People sweat more in warm temperatures, when they exercise, or in response to situations that make them nervous, angry, embarrassed, or afraid.

However, excessive sweating occurs without such triggers. Those with hyperhidrosis appear to have overactive sweat glands. The uncontrollable sweating can lead to significant discomfort, both physical and emotional.

When excessive sweating affects the hands, feet, and armpits, it's called primary or focal hyperhidrosis. Primary hyperhidrosis affects 2 - 3% of the population, yet less than 40% of patients with this condition seek medical advice. In the majority of primary hyperhidrosis cases, no cause can be found. It seems to run in families.

If the sweating occurs as a result of another medical condition, it is called secondary hyperhidrosis. The sweating may be all over the body, or it may be in one area. Conditions that cause second hyperhidrosis include:

• Acromegaly
• Anxiety conditions
• Cancer
• Carcinoid syndrome
• Certain medications and substances of abuse
• Glucose control disorders
• Heart disease
• Hyperthyroidism
• Lung disease
• Menopause
• Parkinson’s disease
• Pheochromocytoma
• Spinal cord injury
• Stroke
• Tuberculosis or other infections

The primary symptom of hyperhidrosis is wetness.

Visible signs of sweating may be noted during a doctor's visit. A number of tests may also be used to diagnose excessive sweating. Tests include:

Tests include:

• Starch-iodine test. An iodine solution is applied to the sweaty area. After it dries, starch is sprinkled on the area. The starch-iodine combination turns a dark blue color wherever there is excess sweat.
• Paper test. Special paper is placed on the affected area to absorb the sweat, then weighed. The heavier it weight, the more sweat has accumulated.

The patient may be also be asked details about the sweating, such as:

• Location
  • Is it on face, palms, or armpits?
  • Is it all over the body?
• Time pattern
  • Does it occur at night?
  • Did it begin suddenly?
  • How long have you had it?
• Triggers
  • Does it occur in response to reminders of a traumatic event?
  • What other symptoms are present (for example, weight loss, a pounding heartbeat, lack of appetite)?
  • Are the hands cold and clammy?
  • Is there a fever?

Treatments may include:

• Antiperspirants. Excessive sweating may be controlled with strong anti-perspirants, which plug the sweat ducts. Products containing 10% to 15% aluminum chloride hexahydrate are the first line of treatment for underarm sweating. Some patients may be be prescribed a product containing a higher dose of aluminum chloride, which is applied nightly onto the affected areas. Antiperspirants can cause skin irritation, and strong doses of aluminum chloride can damage clothing. Note: Deodorants do not prevent sweating, but are helpful in reducing body odor.
• Medication. Anticholinergics drugs, such as glycopyrrolate (Robinul, Robinul-Forte), help to prevent the stimulation of sweat glands. Although effective for some patients, these drugs have not been studied as well as other treatments. Side effects include dry mouth, dizziness, and problems with urination. Beta-blockers or benzodiazepines may help reduce stress-related sweating.
• Iontophoresis. This FDA-approved procedure uses electricity to temporarily turn off the sweat gland. It is most effective for sweating of the hands and feet. The hands or feet are placed into water, and then a gentle current of electricity is passed through it. The electricity is gradually increased until the patient feels a light tingling sensation. The therapy lasts about 10-20 minutes and requires several sessions. Side effects include skin cracking and blisters, although rare.
• Botox. Botulinum toxin type A (Botox) was approved by the FDA in 2004 for the treatment of severe underarm sweating, a condition called primary axillary hyperhidrosis. Small doses of purified botulinum toxin injected into the underarm temporarily block the nerves that stimulate sweating. Side effects include injection-site pain and flu-like symptoms. If you are considering Botox for other areas of excessive sweating talk to your doctor in detail. Botox used for sweating of the palms can cause mild, but temporary weakness and intense pain.
• Endoscopic thoracic sympathectomy (ETS). In severe cases, a minimally-invasive surgical procedure called sympathectomy may be recommended. The procedure is usually performed on patients with excessively sweaty palms. It is not as effective on those with excessive armpit sweating. This surgery turns off the signal which tells the body to sweat excessively. ETS surgery is done while the patient is asleep under general anesthesia. The doctor makes two or three tiny cuts under the arm. The patient's lung is collapsed so the surgeon has more room to work. A tiny camera, called an endoscope, is inserted to guide the surgeon to the appropriate nerve. After the nerve associated with the overactive gland is identified, it is removed or destroyed. The lung is restored to normal, and the wound closed with stitches. The identical procedure is done on the other side of the body. The surgery takes about a half hour. Patients usually go home the next day, but may experience pain for about a week. ETS requires special training. Before having this surgery, make sure your doctor is properly trained. Risks include artery damage, nerve damage, and increased sweating. New sweating occurs in about 50% of patients.

Aluminum Chloride: Initially a patient may need to use it three to seven times a week.  After sweating becomes normal, the person may need to use it only once every one to three weeks.  If skin irritation is a problem, a doctor may temporarily prescribe 1% hydrocortisone cream.

Botox: Swelling goes away in a few weeks. The effect of a single injection can last up to a few months. Some patients need additional injections.

Iontophoresis: Sweating may be reduced after six to 10 sessions. After that, the person may need treatment once every one to four weeks. 

Some of the causes of hyperhidrosis can be serious. Always consult a doctor if you have excessive sweating.

• There is prolonged, excessive, and unexplained sweating.
• Sweating is accompanied or followed by chest pain or pressure.
• Sweating is accompanied by weight loss or most often occurs during sleep.
• If sweating is accompanied by fever, weight loss, chest pain, shortness of breath, or a rapid, pounding heartbeat. These symptoms may indicate an underlying problem, such as hyperthyroidism.

Haider A, Solish N. Focal hyperhidrosis: diagnosis and management. CMAJ. 2005 Jan 4;172(1):69-75.

Hornberger J, Grimes K et al. Recognition, diagnosis and treatment of primary focal hyperhidrosis. J Am Acad Dermatol 2004; 51: 274-86

Fitzgerald E, Feeley TM, Tierney S. Current treatments for axillary hyperhidrosis. Surgeon. 2004 Dec;2(6):311-4, 360.

Solish N, Benohanian A, Kowalski JW. Prospective open-label study of botulinum toxin type A in patients with axillary hyperhidrosis: effects on functional impairment and quality of life. Dermatol Surg. 2005 Apr;31(4):405-13.