What It Is

Hyperhidrosis is a disorder that defines individuals who sweat more than the body would normally need to maintain optimal temperature.  It affects approximately 3% of the population – some 950,000 Canadians – of whom 300,000 have a severe form of the disorder.


It has been previously disregarded as a natural body reaction that most sufferers learn to live with and compensate for in lifestyle, but it has also been shown to seriously affect quality of life. Many sufferers may be conscious of their sweating when making decisions about daily activities. Sweating hands, underarms, feet or face can give the wrong impression in business and personal situations. Hyperhidrosis can have an emotional, social, and physical impact on sufferers.

Types of Hyperhidrosis

There are two types of hyperhidrosis:

Focal hyperhidrosis, also known as primary hyperhidrosis, has an unknown cause. This type of hyperhidrosis is localized to one or more of the following areas:

  • Underarms (axillary hyperhidrosis)
  • Hands (palmar hyperhidrosis)
  • Feet (plantar hyperhidrosis)
  • Face (facial hyperhidrosis)

Although this type of hyperhidrosis has an unknown cause, the way it affects sufferers appears to be related to over-activity of the central nervous system thereby causing an overactive stimulation of local sweat glands.

Generalized hyperhidrosis, also known as Secondary Hyperhidrosis, can be caused by another underlying condition (e.g. endocrine disorders, menopause, obesity, nerve damage, and rarely, some types of drugs). This type of hyperhidrosis generally occurs over the whole body and is usually treated by addressing the underlying condition.


There are several ways to treat focal hyperhidrosis.

Topical Treatments

The application of aluminum chloride hexahydrate (Drysol®) has been shown in clinical study to reduce sweating by approximately 50% for mild hyperhidrosis sufferers.

Most people commonly use antiperspirants and deodorants on a daily basis to reduce wetness and fight odour. However, not all antiperspirants are equally effective. Those containing aluminum chloride and alcohol seem to be most effective.

Initially, the product is applied daily or less (2-3 times per week) so the duration of effect is short. However, over time there can be an increase in duration of effect after each application.

Extra-strength preparations can cause skin irritation and discomfort. Depending on the concentration of aluminum chloride, effectiveness may be limited in moderate to severe hyperhidrosis.


Iontophoresis is appropriate for people with hyperhidrosis of the hands or feet. With iontophoresis, each hand or foot is immersed in a tray containing a water-soaked pad. The pads are connected to a low-intensity electric current that is passed through the liquid. The currents are sent through the skin to disrupt the function of the sweat glands.

In the beginning, the treatment is repeated several times, but once control is achieved, a single treatment can be effective for several weeks. Initial iontophoresis treatment takes about 30 minutes per treatment site at least 4 days per week. There is a potential for skin irritation, and this application is not usually recommended for underarm or facial/head hyperhidrosis.

Botulinum Toxin Type A Injections

Botulinum toxin type A (BOTOX®) injections are appropriate for moderate to severe hyperhidrosis sufferers.

Injection with botulinum toxin type A interrupts the signal from the nerve to the sweat gland to reduce the sweating in the area that is affected. The injection is done with a very fine needle and, for treatment of the underarms, face and head, anaesthesia is often not required as the procedure is well tolerated. For treatment of the hands and feet, local anaesthesia is used to avoid injection discomfort.

The percent reduction in sweating in a clinical study was 83% in 95% of participants. The effect of treatment can be immediate or take up to a week, with the average duration of effect after a single treatment being 7 months; 30% of patients have effects lasting longer than a year.  Side effects, if they occur, are temporary. A rare, reported side effect that may be perceived is increased sweating in other areas of the body (known as compensatory  sweating or paradoxical hyperhidrosis). Other side effects may include pain or bruising at the site of injection.


Surgery is often a last resort when conventional therapies have failed.

Hyperhidrosis of the hands can be treated with a procedure known as endoscopic thoracic sympathectomy (ETS). In ETS, doctors cut or clip the nerves causing abnormal sweating and is often performed on an outpatient basis.

The type of surgery usually done for underarm sweating (axillary hyperhidrosis) is surgical excision of axillary glands. In this operation the sweat glands are actually removed. Some patients report relief from their symptoms immediately after the operation. Follow-ups have shown that sweating remains reduced for at least several years after surgery in many cases.

Risk of compensatory sweating  may also be associated with surgical procedures for sweat reduction.