In many cases of gastro-oesophageal reflux disease (GORD) there is no reason why a person develops the condition.

However, one of the known causes of GORD is a problem with a muscle, known as the lower oesophageal sphincter (LOS), which is located at the bottom of the oesophagus (gullet).

The LOS works in a similar way to a valve. It opens to let food into your stomach, and it closes to prevent any acid leaking back up into your oesophagus.

However, in people with GORD, the LOS can become weakened, which allows stomach acid to pass back into the oesophagus. This causes the symptoms of heartburn, such as a burning pain or a feeling of discomfort in your stomach and chest.

Other causes of GORD can include:

• an increased pressure on your stomach as a result of being overweight or obese
• your stomach taking longer than it should to dispose of stomach acid, a condition that is known as gastroparesis

Gastroparesis is common in people who have diabetes because high blood sugar levels can damage the nerves that control the stomach.

Risk factors

A number of possible risk factors are known to increase your likelihood of developing GORD. These include:

• being overweight or obese – for the reasons mentioned above
• having a diet that is high in fatty foods – the stomach takes longer to dispose of stomach acids after digesting a fatty meal
• using tobacco, alcohol, coffee or chocolate – it has been suggested that these four substances may relax the LOS
• being pregnant – the changes in hormone levels during pregnancy can weaken the LOS and increase the pressure on your stomach
• having a hiatus hernia – a hiatus hernia is where part of your stomach pushes up through your diaphragm (the muscle that is used for breathing)
• stress 

Medication

There are a number of medications that can relax the LOS, leading to the symptoms of GORD.

These include:

• anticholinergics – a type of medication that is used to treat a wide range of respiratory (lung), digestive, neurological (nerve) and infectious conditions
• calcium-channel blockers – a type of medication that is used to treat high blood pressure (hypertension)
• theophylline – a type of medication that is used to treat respiratory conditions, such as asthma and chronic pulmonary obstructive disorder (COPD) (a general term that describes a collection of serious lung diseases, such as emphysema)
• benzodiazepines – a type of tranquiliser that is used to treat serious panic and anxiety disorders
• nitrates – a medication that is used to treat angina (a condition that causes chest pain).