DermNet NZ

Facts about the skin from DermNet New Zealand Trust. Topic index: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z


Hyperhidrosis is the name given to excessive and uncontrollable sweating.

Sweat is a weak salt solution produced by the eccrine sweat glands. These are distributed over the entire body but they are most numerous on the palms and soles (with about 700 glands per square centimetre).

Localised hyperhidrosis is more common than generalised hyperhidrosis. Triggers to attacks of sweating may include:

The sweating usually reduces at night time and disappears during sleep.

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Hyperhidrosis of palms and soles

What is the cause of hyperhidrosis?

The exact cause or causes of hyperhidrosis are unknown. It appears to be due to overactivity of the body temperature centre in the brain (the hypothalamus) transmitted through the sympathetic nerves that control the sweat glands.

Primary hyperhidrosis first appears in childhood or adolescence. It may persist lifelong, or improve with age. Other family members may or may not be similarly affected. It tends to involve both armpits, palms and or soles symmetrically.

Secondary hyperhidrosis as a consequence of a medical disease or condition is less common. Secondary hyperhidrosis is more likely to be unilateral and asymmetrical, or generalised. It can occur at night or during sleep. It may be due to endocrine or neurological conditions, such as:

Localised hyperhidrosis may also be due to:

What is the result of excessive sweating?

Hyperhidrosis is an embarrassing complaint and significantly interferes with many daily activities.


Hands and feet:

Treatment of hyperhidrosis

General measures



Oral medications

Botulinum toxin injections

Removal of sweat glands

Overactive sweat glands in the armpits may be removed by several methods, usually under local anaesthetic.


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