What is hyperhidrosis?
Hyperhidrosis means excessive sweating. It can be localised or affect the whole body.
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. Some of these functions, including sweating, are called “sympathetic”. (This is different from the everyday use of the word and does not suggest any emotional meaning).
Increased sweating is a normal response to a rise in body temperature, and to emotions like anxiety.
A treatment which reduces sweating is called an antiperspirant. This is different from a deodorant, which reduces odour, usually through an antibacterial effect. The two are often combined in the same product.
What causes hyperhidrosis?
Localised symmetrical hyperhidrosis: the commonest type of hyperhidrosis, this affects certain body sites (localised), and both sides equally (symmetrical). The palms, the soles, the skin under the arms, the face and scalp, or combinations of these can be affected. The cause of this type is not known. It often begins in the teens, and tends to improve slowly as you get older. This type of hyperhidrosis is also called focal or primary hyperhidrosis.
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. This type of hyperhidrosis is called secondary hyperhidrosis. Some medicines can also cause excessive sweating, including fluoxetine (Prozac) and similar antidepressants. Sometimes no cause can be found.
Disease or irritation of part of the sympathetic nerve pathway is a rare cause of increased sweating, either generally or in localised areas (usually on one side rather than both).
Anxiety can trigger or worsen hyperhidrosis, but this does not necessarily mean that the affected person is unusually anxious or stressed.
Is hyperhidrosis hereditary?
Hyperhidrosis is a feature of some rare inherited conditions. There is a trend for the common localised symmetrical type to run in families and up to a third of sufferers may have a family member with the condition.
What are the symptoms of hyperhidrosis?
Visible sweat, wet clothes and a clammy handshake can be embarrassing, and can interfere with work and personal relationships.
Hyperhidrosis affects the water-producing (“eccrine”) sweat glands, and not the “apocrine” sweat glands which produce the more oily type of sweat which causes odour, especially under the arms. Therefore bad odour is not a direct result of hyperhidrosis. However, if sweaty feet get soggy inside shoes, overgrowth of harmless skin bacteria can cause a bad smell.
How will it be diagnosed?
Your doctor will assess which kind of hyperhidrosis you have. Depending on the type, you might have tests for an infection, diabetes, thyroid overactivity or other conditions.
Can hyperhidrosis be cured?
When there is an underlying cause which can be treated, the hyperhidrosis can be cured. Surgical treatment can cure some people, but is often associated with side effects and is therefore considered only if other modalities have failed. Otherwise, the aim is to control the condition.
For information about available treatments please go to this page on the website of the British Assocaition of Dermatologists