Sweating: excessive sweating is called hyperhidrosis
Sweating is a normal process that keeps the body’s temperature normal and maintains skin hydration (moisture). Properly hydrated skin on the hand is necessary for a normal grip and for tasks such as turning the pages of a book.
About one per cent of people suffer from excessive sweating. This is known as hyperhidrosis and can be a very distressing and disabling condition. The palms of the hands, the soles of the feet, or the armpits (axillae), are the areas usually affected, but in a small number of people hyperhidrosis occurs over the whole body surface.
People with palmar hyperhidrosis have a slippery grip and a cold, wet handshake. Their sweat drips into computer keyboards, wets paper, and smudges ink. Axillary and plantar (soles of the feet) hyperhidrosis stain and damage clothing and shoes. Although sweat is usually odourless, sufferers are embarrassed and inconvenienced by having sodden clothing and damp hands.
Treatment
Treatment with drugs or applying an aluminium-based substance to the skin can help, but is inconvenient, unpleasant, and temporary. The drugs can cause a dry mouth, and aluminium often causes skin soreness and irritation. Antiperspirants can help some people with a mild problem but in severe cases they are ineffective.
Experts now recommend that patients with severe localised hyperhidrosis should consider either surgery or injections of botulinum toxin.
Sweat glands are stimulated by special nerves from the sympathetic nervous system. The sympathetic nerves to the arm come from the spinal cord in the upper chest. These nerves can be cut, resulting in greatly reduced sweating in the palms of the hand.
This treatment is not so effective for excessive sweating in the armpits. Cutting the equivalent sympathetic nerves to the feet is not recommended, as it will almost certainly interfere with sexual function.
Botulinum toxin, which is also known by the brand name Botox, is a poison produced by a bacterium known as Clostridium botulinum. It is one of the most poisonous biological substances known. It has the effect of blocking nerve impulses. This can cause muscle weakness or paralysis and, in the case of hyperhidrosis, stop the sympathetic nerves stimulating sweat glands.
Tiny amounts of toxin are injected directly into the skin where excessive sweating occurs. Although this can be tedious and uncomfortable, it can reduce or remove sweating for up to a year, after which the injections may need to be repeated.
If you are bothered by a tendency to sweat too much and can’t control it with simple over-the-counter preparations from the chemist, talk to your doctor.
Last Reviewed: 27 February 2002
