The lowdown on heavy sweating

‘Horses sweat, men perspire and ladies glow’, or so the saying goes. …and people who live with hyperhidrosis glow buckets.

Hyperhidrosis simply means excessive sweating. OK, it’s not life-threatening. It won’t even make you ill, but let’s not underestimate the embarrassment and discomfort that clammy hands, squidgy feet and drenched armpits can inflict.

The good news is there are treatments available.

What causes hyperhidrosis?

Hyperhidrosis appears to be linked to overactivity in one of two parts of the body: 

• the hypothalamus, the area of the brain that maintains body temperature, or
• the sympathetic nerves that control sweat glands.

Primary hyperhidrosis often starts in childhood and tends to be localised to the palms, soles and/or the armpits (axillae). The root cause of this category of hyperhidrosis is not known. 

Secondary hyperhidrosis is due to an underlying medical cause. It can often affect the whole body. Some of the possible causes include:

• diabetes
• an overactive thyroid gland
• obesity
• anxiety
• menopause 
• heart problems
• respiratory failure
• Parkinson's disease
• stroke
• nerve damage 
• some medications
• some tumours (rarely).

Hyperhidrosis can be embarrassing and affect daily living

• Hyperhidrosis of the armpits can stain clothing.
• Constantly wet skin can chafe and develop dermatitis and infections. 
• Damp feet can be smelly, or may damage footwear.
• Wet hands can make gripping things difficult and cause electronic equipment like key pads to malfunction. They also mean a cold, wet handshake.

Self-help for hyperhidrosis

• Use topical antiperspirants containing aluminium hydrochloride.  These may help to reduce sweating, and deodorants may help to disguise any unpleasant odour. 
• Wear loose-fitting clothing, made of natural fibres.
• Keep a change or two of socks with you, to change regularly (and bring a plastic bag for the worn ones).
• Don’t wear the same shoes on consecutive days. Allow them to dry out between wears.
• Use absorbent in-soles and change them regularly.
• Use a non-soap cleanser, to avoid drying out your skin from frequent washing.
• Avoid caffeine, which can stimulate your nervous system.

Treatments for hyperhidrosis

Iontophoresis. This has been quite effective for hyperhidrosis of the palms or soles. Available in some New Zealand hospital departments, it involves passing a low-voltage current through the skin, sometimes with a medication that blocks the nerves. Therapy takes about 15-20 minutes and, at first, is required every day, although after a while it is usually required less frequently. It temporarily reduces the production of sweat, but at the same time causes dryness in other parts of the body, including the mouth, nose and vagina. Iontophoresis can also cause skin irritation or dermatitis.

Oral medication. Medicines to block the nerves that stimulate the sweat glands (anticholinergics) may sometimes be prescribed to reduce sweating but may cause side effects such as blurred vision, dry mouth and constipation.

Botulinum toxin. Botox or Dysport injections have been found to be effective for hyperhidrosis of the armpits. They are not currently licensed for use in the palms and soles of the feet in New Zealand. Botulinum toxin stops the sympathetic nerves (which normally control sweating) from stimulating the sweat glands, and the effect may last between six and 12 months. To be effective, multiple injections are needed in each area. Side effects are generally minimal but may include temporary weakness of the nearby muscles.

Surgery to remove sweat glands. Here the sweat glands in the armpits are removed either through liposuction, cutting under the skin or by removing the skin that contains the sweat glands. This third option may require skin grafting if the area removed is large, and it may leave a significant scar.

Sympathectomy. This operation is considered quite major, so may be reserved for very severe symptoms that have not responded to other treatments. It can treat hyperhidrosis of the armpits and palms. It involves cutting or chemically destroying the sympathetic nerve in the spine that supplies the sweat glands in the arm. The operation is effective in 95% of people, but, in half of those having the surgery it can have the unwanted side effect of hyperhidrosis appearing elsewhere in the body.

If you suffer from excessive sweating, you should discuss it with your doctor. He or she can determine whether you need to have any tests for secondary causes, and can also advise you on options for treatment.

Original material prepared by everybody, April 2009.