Hypnotherapy is a type of complementary therapy that uses hypnosis, an altered state of consciousness.
Hypnosis is widely promoted as a treatment for various long-term conditions and for breaking certain habits. This is despite the fact there is no strong evidence to support these uses.
However, hypnosis does seem to have an effect, though scientists disagree about how it works. Some experts see it as a relaxation technique that uses the power of suggestion and relies on the placebo effect.
When might it be helpful?
Irritable bowel syndrome
Some research studies have suggested that hypnotherapy may help with the symptoms of irritable bowel syndrome (IBS), such as abdominal pain.
These studies do not provide any strong evidence for its effectiveness, but the National Institute for Health and Clinical Excellence (NICE) has nevertheless recognised hypnotherapy as a possible treatment for IBS in those who haven't responded to other treatments.
Losing weight and quitting smoking
There is only limited research evidence that hypnotherapy may help some people to lose weight and to quit smoking, so we cannot be certain of its benefit.
Read the 2010 Cochrane review on Hypnotherapy for Smoking Cessation and the 2009 Cochrane review on Psychological Interventions for Overweight or Obesity.
Some studies suggest that hypnotherapy can be beneficial for childhood eczema. It may also be useful for treating other minor skin conditions, especially those made worse by stress, if used alongside medicine.
Anxiety, pregnancy and childbirth
Hypnotherapy is widely promoted as a treatment for anxiety, although a systematic review of the effectiveness of hypnosis for the treatment of anxiety found there was not enough good evidence to support this.
That said, it has shown some promise in preventing anxiety in pregnancy and relieving pain in labour and childbirth.