Excessive Sweating (Hyperhidrosis) - Causes

Authored by Dr Colin Tidy, 23 Jul 2017

Patient is a certified member of
The Information Standard

Reviewed by:
Prof Cathy Jackson, 23 Jul 2017

Primary (idiopathic) focal hyperhidrosis

This type of excessive sweating tends to affect both sides of your body - that is, the palms of both hands, soles of both feet or both armpits. On the rest of the body, you sweat normally.

The exact cause is not known and it is not associated with any other conditions. (The word idiopathic means of unknown cause.) It just seems that the sweat glands in these areas are more active or more sensitive than normal. In some people, it may run in the family so there may be some genetic factor involved in causing it. It usually first develops under the age of 25 years, but it can develop at any age. Men and women are equally affected. It is common and affects about 3 in 100 people.

The severity can vary from time to time. It may come and go and can be made worse by triggers such as anxiety, emotion, spicy foods or heat. Excessive sweating on the forehead, face, scalp and neck soon after eating is called gustatory sweating.

Anxiety about the sweating itself may make it worse. Excessive sweating tends to be a long-term condition but symptoms sometimes improve over time.

If you have the typical symptoms of primary focal hyperhidrosis, you usually do not need any tests. Your doctor may suggest one or more treatments (see below) if normal antiperspirants do not work well.

Secondary focal hyperhidrosis

This is uncommon. It means that the excessive sweating occurs in one particular part of your body because of a known or likely cause. For example, a spinal disease or injury may cause sweating in one leg. Your doctor may suggest some tests to look for an underlying cause.

Generalised hyperhidrosis

This means that you sweat more than normal all over your body. This is less common than primary focal hyperhidrosis. However, it is usually caused by an underlying medical condition. A whole range of conditions can cause a generalised increased sweating. For example:

  • Anxiety disorders.
  • Various heart problems.
  • Damage to nerves in the spinal cord.
  • Side-effects to certain medicines.
  • Various hormone problems (including an overactive thyroid gland).
  • Infections.
  • Certain cancers.

If you have generalised hyperhidrosis your doctor is likely to examine you and do some tests to find out the cause. The treatment depends on the cause.

Further reading and references

I am 63 and for the last 22 years have suffered with excessive sweating on my head and face, which seems to be getting worse.  This is uncomfortable and embarrassing.  If I do anything even slightly...

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