Sweating is controlled by parts of the brain which send signals along nerves to the small sweat glands in the skin.

These nerves are part of the ‘autonomic nervous system’ which controls many unconscious body functions. Increased sweating is a normal response to a rise in body temperature, and to emotions like anxiety.

What causes hyperhidrosis?

Localised symmetrical hyperhidrosis is the most common type of hyperhidrosis and affects certain body sites e.g. the palms, the soles, the skin under the arms, the face and scalp. The cause is not known and it often runs in families. It frequently begins in the teens and tends to improve slowly as you get older.

Generalised hyperhidrosis (affecting the whole body) can be caused by some illnesses including infections, and by some hormonal conditions including the menopause, diabetes and an overactive thyroid gland. Some medicines can also cause excessive sweating, including fluoxetine (Prozac) and similar antidepressants. Often no cause can be found.

Anxiety can trigger or worsen hyperhidrosis, but this does not necessarily mean that the affected person is unusually anxious or stressed. It can be very embarrasing and interfere with work and personal relationships.

How can it be treated?

Most people suffering from hyperhidrosis will have tried commercial antiperspirants which are based on aluminium chloride or similar chemicals.

If these fail, and if the sweating is bad enough to interfere with your work or social activities, you should ask your GP for investigations and advice.

Generalised Hyperhidrosis

Generalised hyperhidrosis is too widespread to treat with lotions, injections or surgery and oral medications can be used to reduce sweating.

Localised Hyperhidrosis

If topical OTC therapies fail, other treatments include formalin soaks, glycopyrrolate solutions, and Iontophoresis.

Botulinum toxin injections are an excellent for localised hyperhidrosis eg for the axillae. It works rapidly and the effect can be seen within 24 hours. The result can last between 9 and 12 months. The treatment can be repeated as needed. Botulinum toxin is less commonly used in facial sweating, palms and soles because it can cause temporary weakness of the face, hand or foot muscles. I give this treatment frequently to professional business people who find that they can’t remove their jackets in meetings as they feel it could create a very bad impression if their client saw severe axillary sweating !

Finally surgery is available for resistant cases. The ‘sympathetic’ nerves which supply the sweat glands can be interrupted surgically, a method called ‘sympathectomy’. This treatment is potentially associated with severe side effects and should only be considered in extreme cases where all else fails. It is carried out by a Vascular Surgeon.

Newer surgical methods involving laser destruction of the axillary sweat glands are currently under investigation.