Sweating is a normal and totally natural process through which the body controls heat. However, some people suffer from excessive sweating, which is also known as hyperhidrosis. To some it is a minor annoyance. But for those who suffer from excessive sweating it is a serious consideration that can affect daily life, relationship and careers. Many people, even some doctors do not understand the problem and dismiss the symptoms as merely troublesome.

Hyperhidrosis is a genetic condition that affects mostly the hands, forehead, feet or underarms. Everyone sweats to some extent. This is an important process to help the body to control its temperature and hydrate the skin. In hyperhidrosis the brain over stimulates the glands that are responsible for sweating. It is common for it to run in families and up to one third of people have another member of the family affected.

It affects 3-5% of the population or in other words 1 in 20 people suffer from severe hyperhidrosis which usually starts during the teens and twenties. Moderate hyperhidrosis is more common and the majority of people suffer from this at some point in their lives. Hyperhidrosis affects men and women, all races and every age group. Excessive sweating can occur at any time, while you are in a cold room, while you are calm, restful and without any stress or anxiety. Most sufferers find the problem distressing and this may worsen their condition. However, many things can trigger normal sweating and this is also true for hyperhidrosis – it is just the amount of sweating that varies.

What triggers excessive sweating?
  • Exercise.
  • Heat or cold.
  • Alcohol, coffee or tea, smoking, hot or spicy food.
  • Stress, anxiety or strong emotions.
  • Certain times of the day.
What problems does excessive sweating cause?

Those who are plagued with excessive sweating are always reluctant to interact fully in social and business settings, never knowing when they will experience the embarrassment of profuse sweating. People who experience hyperhidrosis are reluctant to share a hug, get close to other people and even shake hands. They feel they need to shower more often, change their clothes several times a day and even avoid social contact. This can affect their work performance and self-confidence.

Types of hyperhidrosis?


This is the most common form which affects the areas such as the scalp, face, hands, trunk and thigh, feet and in about 30-40% of cases, the armpits.


This is usually caused by an underlying medical conditions such as overactive thyroid gland, medications and neurological diseases and causes excessive sweating of the entire body, so when treated, sweating usually stops.

How does this treatment work?

Muscle relaxants or anti-wrinkle injections have been found to be effective in the management of excess sweating. The chemical that is released by nerve endings to stimulate muscle contraction, acetylcholine, is the same chemical that causes sweat glands to produce sweat.

Muscle relaxants work, in both cases, by preventing the release of this chemical from nerve endings, thereby blocking muscle contraction (when injected in the area of facial muscles) and blocking excessive sweat production (when injected into the skin of the underarms).

Muscle relaxants work by blocking the communication between the sympathetic nerves (which innervate the apocrine glands) and the sweat glands. The effect mimics surgery without the risks of nerve damage, scarring, and compensatory hyperhidrosis elsewhere in the body.   By blocking the sympathetic nerve transmission the muscle relaxant injection stops the over-production of sweat, allowing perspiration to be reduced to “normal”, easily managed levels.

The injection is done with a very fine needle and, for treatment of the underarms, face and head; anaesthesia is often not required as the procedure is virtually painless.

Does it work?

Clinical studies show muscle relaxant injections produce a 90% reduction in sweat production. This drops the sweat level to easily managed levels for most patients so that sweating rarely, if ever, interferes with their daily activities.

How long does it last?

The effects usually last 6 to 12 months. Case studies show that with repeated injections the sweat control becomes even better (patients become more confident and the emotional component of sweating is lessened) and tends to last longer.

Is this procedure painful?

The treatment of armpits usually starts with a sweat test to mark out the affected area. Tiny injections using insulin needles are then made to evenly distribute the muscle relaxant product. Usually no analgesia is required – brief icing with an ice pack is more than sufficient. A topical numbing cream can be applied if required by the patient. Treatment of feet and palms can be very painful as they are very sensitive areas and will require anaesthesia or sedation. Results in these two areas tend to be variable and therefore we have chosen not to treat them at Zinc Clinic.

Can the face and forehead be treated?

Facial sweating can also be treated. Anti-wrinkle injections can be used in some areas, but because they also relax the muscles of facial expression, they cannot be used in all areas as they may affect one’s ability to express normally. They are effective for areas such as the upper lip and forehead in particular, and may have the added benefit here of reducing wrinkles in these areas if present.

Are there any side effects?

In clinical trials a small number of patients experienced increased sweating in other parts of the body. Although the injection is given into the skin it is possible that a small amount may spread into the nerves supplying the muscles. In clinical trials about 0.7% of patients reported a slight weakness in the arm when the armpit was treated. This did not last and got better without intervention. As with any injection, there may be slight discomfort at the injection site and a small amount of bruising in the area treated.