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What is Hyperhidrosis?

​Hyperhidrosis means excessive sweating. It can be localised or affect the whole body. Sweating is controlled by the brain, which sends signals along nerves to the small sweat glands in the skin. Increased sweating is a normal response to a rise in body temperature, and to emotions such as anxiety. Hyperhidrosis can be idiopathic (unknown cause), due to diseased or irritated nerves, thyroid disorders, diabetes mellitus and occasionally as a side effect of certain medications such as antidepressants.


​Visible sweat and wet clothes are what most patients experience, sometimes even during cool and calm situations. Sometimes, overgrowth of harmless skin bacteria can cause an unpleasant smell in patients with hyperhidrosis.

Treatment and drugs

Localised hyperhidrosis

Aluminum chloride is the usual active ingredient in commercially available antiperspirants. They should be applied at night only, to dry skin. However, local irritation can be a side effect.

Iontophoresis is a method of passing a small electric current through areas of skin immersed in a dish of water. It is used for the armpits, palms and soles. It is a way of getting glycopyrrolate into the skin. The treatment needs to be done regularly every 1-2 weeks and lasts 10-20 minutes. Iontophoresis does tend to cause a tingling sensation.

Botulinum toxin derived from bacteria can be injected into the skin in very small carefully controlled doses to block the action of the nerves which activate the sweat glands. The effect usually lasts 2-6 months, although some patients may continue to benefit for 12 months, and the treatment can be repeated. Botulinum toxin is more commonly used in the underarms and not the palms and soles because it can cause pain and temporary weakness in hand and foot muscles.

Endoscopic thoracic sympathectomy may be considered for localized hyperhidrosis when other treatments have failed. It is most useful for severe hyperhidrosis of the palms and face. This is a major operation, performed under general anaesthetic and is best performed by a trained surgeon.

Other surgical methods apply only to the underarm skin, especially when only a small area is involved. They include the removal of a wedge of skin containing the overactive sweat glands, or the scraping away of the sweat glands from a flap of skin or from the underside of the skin through a small hole.

Generalised hyperhidrosis

You can take medications which block the chemical signal between the nerves and the sweat glands. Propantheline, oxybutynin and glycopyrrolate are anticholinergic drugs widely used. Unfortunately, anticholinergics sometimes cause side effects including a dry mouth, blurred vision, tummy cramps, constipation, and difficulty in passing urine. They may be harmful for people with glaucoma and some other conditions. A small dose is used at first and gradually increased. Some people get relief from sweating before significant side effects occur, but for others the side effects begin before they reach a dose high enough to control sweating. It is important to consult your doctor before consuming such medications.
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