Hypnotherapy can help relieve severe chest pain not caused by a heart condition, research suggests.
Some chest pain remains a mystery
The cause of non-cardiac chest pain (NCCP) is unknown, and it is notoriously difficult to treat.
A small UK study in the journal Gut found 12 out of 15 people treated with hypnotherapy reported an improvement in their symptoms.
In contrast just three out of 13 people treated by supportive listening and a dummy drug reported an improvement.
Around a third of patients with chest pain thought to be caused by coronary artery disease turn out to have no identifiable cause for their pain.
Some experts believe it may be linked to psychological problems, or heartburn.
Many people are often severely incapacitated by it, despite assurances that there is nothing to worry about.
Young women seem to be particularly prone to the condition.
Researchers at Manchester's Wythenshawe Hospital randomly divided 28 patients with the condition into two groups.
One group received 12 sessions of hypnotherapy over 17 weeks; the other group were given "supportive therapy" plus dummy medicine.
Some 80% of the hypnotherapy group reported significant pain relief, although there was no change in frequency of bouts of pain.
Hypnotherapy also significantly improved the sense of overall wellbeing and reduced the use of painkillers and other drugs prescribed to control the condition.
By contrast, the group treated with supportive therapy increased their drug intake.
Hypnotherapy did not affect levels of anxiety or depression, however, which remained the same as before.
Brain scans of patients treated with hypnotherapy for other conditions show that it directly affects a region of the brain which processes the emotional content of a painful stimulus.
Hypnotherapy can also cut levels of gastric acid produced by the stomach.
Lead researcher Professor Peter Whorwell told the BBC News website it could be that hypnotherapy reduced NCCP by reducing the sensitivity of the gullet, or the strength of its contractions.
However, he said it was also likely that hypnotherapy helped patients to relax.
He said: "What is clear is that simply reassuring these patients that there is nothing seriously wrong is not enough. We have shown that if you can modify their symptoms and improve their stress levels then they seem to do quite well."
The researchers acknowledged that hypnotherapy was labour intensive and therefore expensive.
But they argue that so too are many investigations and drugs given to patients with non-cardiac chest pain.
Previous research carried out by the same authors on patients with irritable bowel syndrome found most of them remain well in the long term, requiring far less medication and far fewer visits to their doctors.
Cathy Ross, of the British Heart Foundation, said: "This study supports others that have shown that some patients can benefit from alternative treatments such as hypnotherapy."
However, Professor Richard Mayou, of the University of Oxford, was sceptical that hypnotherapy had any effect other than to relax the patient.
He said NCCP could be treated by using intensive psychological treatment, which might include hypnotherapy.