Acid reflux is caused by acid travelling up towards your throat from leakage of acid from the stomach, causing heartburn and discomfort. When this happens regularly, it is referred to as gastro-oesophageal reflux disease (GORD).
People of all ages can suffer from acid reflux from time to time. There is no obvious cause of acid reflux. In the UK, there are several medicines licenced for the treatment of acid reflux.