Most of us go red when, for example, we receive a compliment or have to give an impromptu speech - it's perfectly normal. But what would you do if you blushed so often that you ended up avoiding people? It's a problem that Enrique Jadresic, professor of psychiatry at the University of Chile, is all too familiar with. Now, having had an operation to relieve his condition, he has written a book, When Blushing Hurts (IUniverse), both to encourage patients to seek help and to educate doctors in how to treat the problem.

Jadresic started noticing his blushing at 14 and the problem grew steadily worse. "When I was working in a hospital I was in a constant state of alert because of the possibility of meeting either one of my students or one of my patients, and that meant almost invariably turning red. For a figure of authority it's a torment to blush in front of students or patients for no reason."

If he had to give a presentation, rather than worrying about what to say, he was anxious about the colour his cheeks would turn. He could improve his symptoms by taking beta blockers but he would still frequently receive comments from patients and friends such as, "There you go up the cherry tree again, doctor". Worse, it was impacting on his career. He was offered the chance to become president of the Chilean Society of Neurology, Psychiatry and Neurosurgery, but was reluctant to take such a high-profile post because of his condition.

Then one day, he read about an operation that could help stop blushing. The operation, called an endoscopic transthoracic sympathectomy, involves cutting or clamping part of the sympathetic nerve - the nerve that causes sweating and blushing when stimulated. It runs from the belly button to the neck, but the easiest way to reach it is by making incisions beneath the armpit. "After the operation," says Jadresic, "I no longer turned bright red whenever I heard someone say my name."

Most experts think the cause of severe blushing, also known as pathological blushing or erythrophobia, is psychological. Once someone begins to get embarrassed about going red they enter a vicious circle: they notice that they blush in embarrassing situations so begin to get anxious about blushing in the future. The more they worry, the more easily they blush; this leads to blushing in "normal" situations, which can appear strange to others (why are they blushing? Do they fancy me? What have they been up to?). Many people with this problem develop social anxiety disorder and, indeed, blushing is a recognised symptom of this condition.

"Blushing is assumed to peak during adolescence," says Robert J Edelmann, professor of forensic and clinical psychology at Roehampton University and author of Coping With Blushing (Sheldon Press). "However, this has more to do with embarrassment potential being higher during adolescence (not yet a grownup but no longer a child means plenty of scope for social failings) rather than blushing propensity. Embarrassment potential is then assumed to decline with age. Because of this, fear of blushing can actually increase with age." As the years go by, it becomes less socially acceptable to blush, which only adds to the embarrassment and fear.

But if it's a purely psychological problem, why would an operation work? "The most likely explanation is that people have the surgery and say, 'Thank goodness I'm all right now,'" says Edelmann. "You remove the need for the person to worry that they might blush." In other words, having an operation might act like a placebo. However, there is also a physical explanation for why the operation can succeed. The sympathetic nervous system is usually activated in dangerous or frightening situations, causing the pupils to dilate, the heart to beat faster, and the blood vessels in the skin to fill up causing sweating and blushing. Therefore, cutting the part of the sympathetic nerve that supplies the skin in the face should stop the face turning red when embarrassed.

As yet, there aren't any reliable clinical studies to confirm the effectiveness of surgery and the procedure can have some unpleasant side effects. The sympathetic nervous system is needed for the body to regulate its temperature through sweating. If you are unable to sweat from the face, the rest of the body has to compensate, leading to excessive sweating elsewhere. "I've had people who say they have to change their shirt six times a day because of sweating," says Edelmann. While Jadresic says that he sweats more than he did before his operation, he feels the benefits outweigh the side effects. These symptoms occur in more than half of all cases. Surgery can also lead to chronic pain and damage to the nerve supply to the eye (in around one in a hundred operations).

Despite these side-effects, surgery may seem like a magical cure for many. "The operation is so simple - it takes no more than 20 minutes," says Jadresic. He does, however, have concerns about it becoming the standard treatment for pathological blushing." Satisfaction rates among his patients is high but they undergo psychiatric screening before being operated on, and if the procedure becomes more widely available people may be tempted to have surgery before trying other ways of reducing their anxiety. "Other treatments should be used first - psychotherapy, drugs or both. Surgery should be a last resort."