Gastro-oesophageal reflux: what causes it?
If you suffer from gastro-oesophageal reflux (GOR), often just called reflux, you’ll know the symptoms well. But what causes reflux and is there anything that you can do to reduce your risk of developing it?
What happens when you have reflux?
Your oesophagus is the tube that runs from your mouth to your stomach - some people call it the food pipe. Where the oesophagus joins the stomach, there is a ‘valve’ or band of muscle called the lower oesophageal sphincter (LOS). The lower oesophageal sphincter opens after you swallow to allow food to pass from the oesophagus into your stomach, and then closes again to prevent the acidic stomach contents from coming back up into your oesophagus.
In people with reflux, the lower oesophageal sphincter is weakened or relaxes when it shouldn’t, allowing stomach acid (and sometimes stomach contents) to flow up into the oesophagus. This reflux of stomach acid is irritating to the lining of the oesophagus, and can cause symptoms such as heartburn.
Causes of gastro-oesophageal reflux
The following list of things can increase the risk of developing reflux and/or make reflux worse.
A hiatus hernia is when the upper part of the stomach slides up through the gap in the diaphragm into the chest cavity. The diaphragm is the muscle that separates the chest from the stomach. Normally, the gap is only wide enough to allow the oesophagus through it.
The hiatus hernia reduces the efficiency of the LES, which can result in reflux. Also, in normal circumstances, the opening in the diaphragm is thought to act as another sphincter around the lower end of the oesophagus. If this opening is too big it will not work in this way.
Your risk of developing reflux may be increased if you have family members who are affected. This may be related to an inherited weakness of the lower oesophageal sphincter.
Smoking and alcohol
The lower oesophageal sphincter is known to be relaxed by smoking and alcohol consumption, making reflux worse.
Overweight, pregnancy and reflux
Being overweight or obese or being pregnant can increase the pressure on the abdomen and weaken the lower oesophageal sphincter, causing the stomach contents to reflux up into the oesophagus.
Changes in your hormones during pregnancy can also contribute to reflux.
Overeating or eating just before going to bed can worsen reflux symptoms.
Also, digesting large fatty meals can leave the stomach with an excess of acid, increasing the risk of acid refluxing into the oesophagus.
Food and drinks that can cause or aggravate reflux
Some foods and drinks tend to worsen reflux symptoms by increasing the amount of acid in the stomach or helping relax the lower oesophageal sphincter. They may include:
- fried or fatty foods;
- spicy foods;
- peppermint or mints;
- tomato-based foods;
- carbonated (fizzy) drinks;
- coffee and other caffeinated drinks; and
- citrus fruits or drinks.
Medicines that may cause reflux
Some types of medicines can increase the risk of having reflux or make reflux worse. Some examples include:
- Certain painkillers, including non-steroidal anti-inflammatory drugs (NSAIDs). These include medicines such as aspirin and ibuprofen. Codeine can also increase reflux.
- Anticholinergics such as oxybutynin (brand name Ditropan), which is used to treat an overactive bladder. These medicines can increase the tendency of the lower oesophageal sphincter to relax. Older people are particularly sensitive to these medicines.
- Tricyclic antidepressants.
- Theophylline, e.g. Nuelin SR (sometimes used in the treatment of bronchitis, emphysema and asthma).
- Calcium channel blockers (these medicines are usually used to treat high blood pressure and angina).
- Bisphosphonates (medicines used in the treatment of osteoporosis).
Check with your doctor if you take these types of medicines and seem to be having regular episodes of reflux. Do not stop taking your medicines without consulting your doctor.
Bending and straining
Straining can increase the pressure in the abdomen and thus cause reflux, and sometimes also hiatus hernia. The same mechanism (plus gravity) explains why you may experience reflux when you bend over at the waist.
Many people who suffer from reflux find that lying down can also worsen reflux symptoms.
What to do about reflux
Many of these risk factors can be addressed with simple self-help measures. Talk to your doctor if you are concerned about your reflux or self-help measures are not helping. There are gastro-oesophageal reflux treatments available over-the-counter and on prescription.
2.National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms and causes of GER & GERD (updated Nov 2014). https://www.niddk.nih.gov/health-information/digestive-diseases/acid-reflux-ger-gerd-adults/symptoms-causes (accessed Feb 2017).
3. Gastro-oesophageal reflux (published March 2016). In: eTG complete. Melbourne: Therapeutic Guidelines Limited; 2016 Nov. http://online.tg.org.au/complete/ (accessed Feb 2017).