It says that practices are increasingly looking at text messages as another way of communicating with patients, with uses including reminding patients about appointments, to take medication, communicating test results or checking on a patient's progress.

The MDU says it is unwise to rely on patients' implied consent to allow the practice to communicate with them in this way. It advises it is better to adopt a cautious approach and receive the patient's express consent.

Dr James Armstrong, MDU medico-legal adviser, said: ‘While GPs may publicise a text message service to patients on the practice website, practice leaflet and through posters in the waiting room, many patients may still not be aware of the service. They might be surprised to receive a text message from the surgery if they had not given their specific consent and this could lead to a complaint, particularly if the unexpected message is somehow picked up by someone else.'