Hyperhidrosis (excessive sweating)

Sweating is a physiological body function that helps regulate body temperature when we are hot or do exercise. If your sympathetic nervous system is over-active, you may sweat more than you need to, for example, sweating when your body doesn't need to cool down.

There are two types of hyperhidrosis:

• Primary - This type is more common and the cause is not known. The condition can happen all the time, or every now and then. Usually, the condition starts when you are a child or teenager and may last all your life
• Secondary - this type causes sweating all over your body. It is usually caused by a disease that affects your endocrine (hormonal) system such as diabetes or having an over-active thyroid gland. It can also be caused by certain cancers, menopause and obesity.

How is hyperhidrosis diagnosed?

To diagnose this condition, a dermatologist gives the patient a physical exam. This includes looking closely at the areas of the body that sweat excessively. A dermatologist also asks very specific questions. This helps the doctor understand why the patient has excessive sweating.

Sometimes medical testing is necessary. Some patients require a test called the sweat test. This involves coating some of their skin with a powder that turns purple when the skin gets wet.

To find an underlying medical condition, other medical tests may be necessary.

How is hyperhidrosis treated?

There are several treatments for hyperhidrosis:

• Special antiperspirants - these address underarm hyperhidrosis by making sweat thicker which causes your pores to block
• Iontophoresis - uses a small electric current to stop sweat glands from working. However, the effect is only temporary and the treatment needs to be repeated at least every week
• Injections - block the nerves that control the sweat glands. The injections need to be repeated about every 3-6 months. The body can develop resistance to the drugs used, making the treatment less effective over time. There are risks associated with the long-term use of injections.
• Medication - oral medication to stop your sweat glands from being stimulated
• Thoracoscopic sympathectomy - a surgical procedure to cut or clamp the sympathetic nerves.