Acid reflux causes

Acid reflux, or simply reflux, is the condition seen when the acidic contents of the stomach leak backwards and upwards into the oesophagus (gullet) or mouth.

In normal circumstances, a muscular valve lying between the gullet and the stomach prevents reflux occurring - it is designed to allow food to pass only in one direction, from the mouth into the stomach. However, this mechanism can sometimes fail.

There are several health problems and conditions which may cause or be associated with acid reflux:

• Hiatus hernia – this structural abnormality arises when part of the stomach squeezes through the opening in a large muscular sheet called the diaphragm, separating the chest from the abdomen. In health, the diaphragm helps to keep acid in the stomach. A hiatus hernia makes it easier for stomach acid to escape from the stomach into the gullet and mouth

• Indigestion – symptoms of indigestion are common and caused by a disturbance in the normal process of digestion when food is eaten. This can lead to the stomach staying fuller for longer, giving rise to a number of symptoms, including the tendency for acid reflux. Many episodes of indigestion are linked to less than healthy eating habits (see below for more information)

• Pregnancy – many pregnant women experience symptoms of acid reflux during the latter stages of pregnancy. As the unborn baby grows, it exerts upwards pressure on the stomach, encouraging the acidic contents in the mother’s stomach to escape into her gullet. Symptoms tend to worsen as the baby becomes larger, but these usually resolve soon after delivery

• Being overweight or obese – this puts extra pressure on your internal organs, including the stomach, perhaps in the same way that a large baby might before birth. Not only can being overweight force acid out of the stomach, it can also weaken the valve between the gullet and stomach.

• Gastro-oesophageal reflux disease (GORD) - GORD is a digestive disorder that affects the lower oesophageal sphincter (LOS), a band of smooth muscle which links your oesophagus to your stomach. Over time, long-term dysfunction in this muscle long-term can result in GORD and give rise to symptoms including recurrent acid reflux. 

• Low stomach acid – Low stomach acid, as opposed to too much, surprisingly affect the functioning of the LOS too and can give rise to symptoms of acid reflux.

The way you treat your digestive system has a significant influence on whether or not you are likely to experience acid reflux. Many of these lifestyle factors are shared with the tendency to develop indigestion:

• Eating too quickly and not spending enough time chewing will make you more likely to suffer from acid reflux. As you take time to chew, your stomach prepares better for the arrival of food, stimulating the correct balance of stomach acid. This allows you to digest food better, reducing the chances of indigestion
• Heavy, fatty meals will be more likely to result in acid reflux. Large meals take longer to digest and fatty foods stay in your stomach longer. As your stomach takes longer to empty, the likelihood of acid reflux occurring increases. This is particularly so if you eat late at night and before going to bed
• Posture has a big influence on acid reflux, simply because of gravity. Lying down or going to bed immediately after a meal increases your chances of acid escaping from your stomach, as does bending down. In these states, your stomach is at approximately the same level as your mouth, making it easier for your gastric contents to spill out
• Exercising immediately after eating, even if it is a light workout, can result in acid reflux and heartburn. When you exercise, blood is diverted away from your digestive tract to the skeletal muscles. This slows down the digestive process so food stays in your stomach for longer. In addition, abdominal pressure increases with exercise and this may force food upwards out of your stomach.
• Smoking may cause acid reflux for several reasons. Firstly, it reduces muscle tone, so weakens the valve between gullet and stomach. It also stimulates an increased production of stomach acid making any leakage into your gullet more irritating, and reduces the production of saliva which would normally neutralise the acid in your stomach.

Certain foods will not help if you suffer from indigestion, acid reflux or heartburn, either because they are difficult to digest, or because they cause abnormal secretion of digestive juices.

These include:

• Spicy foods
• Fatty, creamy or fried foods
• Extremely hot or cold foods
• Chocolate and caffeine
• Alcohol
• Citrus fruit

Read more about the foods to eat if you have acid reflux.

A number of types of medicines from your doctor or pharmacy may lead to an increased tendency for digestive problems or gastric irritation and consequent symptoms. This list includes muscle relaxants, some blood pressure medications and certain classes of pain-killers and anti-depressants.

If you suspect that the medication you are taking is causing you to experience indigestion or acid reflux, it is worth consulting with your doctor to find a substitute medicine suitable for you to take.

Join experts Eileen Durward and Ali Cullen in the beautiful A.Vogel garden as they talk all about digestion including their tips on how to improve your digestion and how bitter herbs can make a huge difference to helping your digestive problems.