The sympathetic nerves supply the sweat glands in the body. For some unknown reason, some people have excessive sweating in the palms of the hand (palmar hyperhidrosis). These people also have too much sweating in the feet as well.
Excessively sweaty palms are not life-threatening, unless you work around electrical circuits. But they can be socially embarrassing and when writing, the paper can become wet and the ink smudges.
Medical treatment including hand creams can sometimes help. Iontophoresis has also been tried.
The best chance of success is to divide the portion of the sympathetic chain that supplies the sweat glands in the hand. Each chain lies over the neck of the 2nd rib in the chest wall, normally covered by the lung. Previously, one could have a very painful operation from the back, where the back of each 2nd rib is resected and the sympathetic chain is cut.
With the development of better scopes, we can now insert a thoracoscope in-between the ribs and cut the sympathetic chain from the inside of the chest wall. Under general anaesthesia, both sides are done in this minimally invasive operation. Typically, patients stay one night in hospital and go home on the following day. They usually take 2 weeks off work as there will be some discomfort afterwards.
What is the success rate of this operation ?
Provided the sympathetic chain can be seen, it is more than 90%. During the same operation, whilst the patient is asleep, each side is done and the success is shown by an increase in the temperature of each palm shortly after the sympathetic chain is divided.
What are the risks ?
Because of the difficulty of ventilating small lungs, this operation is usually offered to people above the age of 16. The sympathetic chain must be seen and it is more difficult in people who smoke as such patients often have many secretions in the lungs (which have to be deflated in order to uncover the chain). Serious risks such as bleeding, infection, and damage to the lungs are uncommon. But although the hands are dry, almost every patient will notice increased sweating elsewhere in the body. Typically, this occurs in the front and back of the lower chest, and occasionally in the front of the thighs. This operation is irreversible and patients must be aware of this before agreeing to have the operation. The feet are supplied by a different nerve and somewhat surprisingly, a few patients have noticed less sweating in the feet after the hands have been treated.