Excessive sweating – how is it treated?

What causes hyperhidrosis and how is it diagnosed?

There are three basic types of hyperhidrosis: 

• Primary (idiopathic) focal hyperhidrosis occurs in one or more 'focal' places: palms of the hands; soles of the feet; armpits; face/scalp. It usually occurs equally on both sides of the body. This type of excessive sweating is of unknown cause and is not associated with any other conditions, but can run in families. Symptoms may be triggered by emotions or anxiety, or by spicy foods and heat, or there may be no obvious trigger at all. If symptoms are typical of this type of hyperhidrosis, no tests are needed.

• Secondary focal hyperhidrosis occurs in ‘focal’ places but not symmetrically, suggesting a specific cause such as spinal injury or other illness. Your doctor may wish to perform some tests to establish the underlying cause of this type of hyperhidrosis.

• Generalised hyperhidrosis refers to excessive sweating that occurs all over the body. This type of hyperhidrosis is usually associated with another medical condition, such as heart problems, anxiety, spinal disorders, hormonal disorders, infections or side-effects of medication. Your doctor may wish to perform tests to establish any underlying causes.

What hyperhidrosis treatments are available?

You can try to avoid excessive sweating or reduce it by avoiding triggers like spicy food or heat. You can also try changing soaps or other products, avoiding clothes made from man-made fibres, and using antiperspirants as opposed to deodorants. Absorbent foot powders may help disguise excessive sweating of the feet. However, if these measures don’t help, you may want to consider other treatment options:

• Drug treatments: If anxiety is a trigger for excessive sweating, a beta-blocker (as used for high blood pressure) or anticholinergic medication such as propantheline bromide is a possibility.  However, both of these types of drugs may need to be used at high doses to achieve results, and this can lead to unwanted side-effects.

• Aluminium chloride based antiperspirants: These are stronger than traditional antiperspirants. They are thought to work by blocking the openings of the sweat ducts, and are effective on underarms; they can also be effective on the hands and feet. 

• Iontophoresis: This involves submerging the area in a container of water and passing a small electric current through the water. It is not known exactly how iontophoresis acts to reduce excessive sweating, but it possibly disables the sweat glands. The treatment is not painful or dangerous, but might cause temporary ‘pins and needles’. It is generally an effective hyperhidrosis treatment for the hands and feet. Several sessions, usually 6-10 are needed to see an improvement and maintenance sessions are needed to continue the benefits.

• Botox (botulinum toxin): This works by disabling the nerves that control the sweat glands. It is generally effective for excessive sweating in the underarm area, but is not approved for treating the hands and face due to the risk of disabling nearby muscles. The effects usually last between 4 and 12 months, so you need to have repeat treatments.

• Surgery: If none of the above options are effective, surgery can be an option. Endoscopic thoracic sympathectomy is done under general anaesthetic; an endoscope and surgical instruments are placed into the chest cavity through a small hole and the surgeon cuts or clamps the sympathetic nerves that carry the nerve signals that initiate excessive sweating in the upper body and face. Surgery is not normally performed for excessive sweating in the feet.

Are there any complications of hyperhidrosis treatment?

The side-effects of drug treatment for excessive sweating can include a dry mouth and blurred vision. Aluminium chloride antiperspirants can lead to skin irritations. Iontophoresis can cause side-effects such as a dry or sore mouth and throat, and dizziness, for up to 24 hours after each session. Some people get mild 'flu like' symptoms for a day or so after Botox treatment, and the sites of the injections can be sore for a few days after treatment. Rarely, a severe allergic reaction can occur after a Botox injection.

As with any operation, hyperhidrosis surgery does carry some risks such as damage to nearby tissue or infection. If nerves are cut to reduce excessive sweating in the palms, this can sometimes lead to a compensatory increase in sweating elsewhere, such as the chest or groin.

Weighing up the options

All medical treatment choices involve weighing up the benefits to be gained by a particular therapy and the potential side effects. If your hyperhidrosis is affecting your life significantly, the benefits may be far greater than the risks.

Profile of the author 

Dr Kathryn Senior is an acclaimed medical journalist who has written over 500 feature articles for leading international journals within The Lancet group. As Senior Writer at Freelance Copy she produces high quality scientific and medical content for websites and printed publications for companies and organisations in the health, medical and pharmaceutical sectors.