Indigestion is a general term used to describe discomfort or pain in the upper abdomen or chest, usually after meals. An alternative term is ‘dyspepsia’. When a burning discomfort is felt behind the breast bone, it is known as heartburn.

Pain in the upper abdomen may come and go. For some people it can be relieved by food, especially if it feels like a hunger pain, although for others it can occur after eating. It can occur by day or at night, when it may be relieved by a snack or a drink of milk. Alternatively, it can occur without any relation to food at all.

The stomach may feel full soon after starting to eat, so that it is difficult to finish a meal, or there may be an uncomfortable sense of fullness or bloating after a meal. The word ‘indigestion’ may also be used to describe nausea, retching or even vomiting after food.


Symptoms may vary considerably depending on the individual affected.


This is normally felt along with discomfort in the upper abdomen

Gastro-intestinal disturbances

A sufferer of indigestion may feel nausea and feel only able to eat small amounts. They may also experience flatulence and belching and hear loud sounds originating from the intestines. Bowels movements may also be affected with sufferers often suffering from constipation or diarrhoea or intervals of each.

How we get indigestion

The stomach produces a strong acid that helps digest food and protects against infection. A layer of mucus lines the stomach, oesophagus and intestines to act as a barrier against this acid. If the mucus layer is damaged, acid can irritate the tissues below. Long-term irritation of these tissues may also lead to peptic or duodenal ulcer a complication of indigestion.

Risk Factors


People who are over forty-five are more likely to have indigestion and it is generally related to peptic ulcer (see Complications)


Smoking increases the risk of and may cause indigestion and ulcers.

Diet and alcohol

Fatty foods and alcohol can cause indigestion, aggravate ulcers and lead to disorders of the pancreas and gallbladder which in turn can result in indigestion.


Certain prescription drugs as well as over-the-counter medications can irritate the stomach lining. These medications include aspirin, anti-inflammatory drugs, some antibiotics, digoxin, theophylline, corticosteroids, iron (ferrous sulphate), oral contraceptives, and tricyclic antidepressants.

Disorders of the pancreas and gallbladder

These include inflammation of the gallbladder or pancreas, cancer of the pancreas, and gallstones.


Indigestion often accompanies an emotional upset, because the part of the nervous system involved in the so-called “fight-or-flight” response also affects the digestive tract. People diagnosed with anxiety or depression frequently have problems with indigestion. Many people in the general population, however, will also experience heartburn, “butterflies in the stomach,” or stomach cramps when they are in upsetting situations–such as school examinations, arguments with family members, crises in their workplace, and so on. Some people’s digestive systems appear to react more intensely to emotional stress due to hypersensitive nerve endings in their intestinal tract.


By a bacteria known as Helicobacter pylori. This bacterium lives in the tissues of the stomach and causes irritation of the mucous lining of the stomach walls. Most people with a Helicobacter pylori infection do not suffer from indigestion, or indeed suffer from any problems with the stomach as a result of the infection, but the bacteria tends to cause peptic ulcers in those who have risk factors for developing indigestion.

Infection is very common and it is estimated that more that a billion people worldwide are infected by the bacteria Helicobacter pylori. It is believed that the bacteria are transmitted orally, by means of drinking or eating food or water that may be contaminated with the bacteria. This is more likely to occur in situations where individuals are living in crowded, unsanitary conditions.

Other disease states

Any condition that affects the stomach emptying, such as diabetes or those that affect the movement of the intestine, such as irritable bowel can increase chances of indigestion.


Gastric or Duodenal ulcer

Gastric and Duodenal Ulcers are not necessarily a complication of indigestion but indigestion may in fact be the main symptom with which a person may first complain when suffering from a gastric or duodenal ulcer.

A peptic or duodenal ulcer is a small erosion (hole) in the gastrointestinal tract. Duodenal ulcer is the most common and occurs in the first twelve inches of small intestine beyond the stomach. Ulcers that form in the stomach are called gastric ulcers. An ulcer is not contagious or cancerous. Duodenal ulcers are almost always benign, while stomach ulcers may become malignant.

The direct cause of peptic ulcers is the destruction of the gastric or intestinal mucosal lining of the stomach by stomach acid. The most common causes of ulceration are thought to be infection with the bacteria Helicobacter pylori and /or the long-term use of anti-inflammatory medication. Other risk factors that are thought to contribute to the formation and worsening of ulcer are similar to those for indigestion. These include smoking, stress, diet and age (with increasing age, risk of ulcers also increases).

Gastric and duodenal ulcers can be distinguished from each other as their symptoms differ. Typically the pain of a duodenal ulcer is localized in the upper abdomen slightly right to the midline of the body. It is often possible to point to the site of pain with a single finger. The pain is dull and is most likely to occur when the stomach is empty, especially at night. It is relieved by food (but may be aggravated by fatty foods) and antacids. The pain of a gastric ulcer is in the same area but less well localized. It is often aggravated by food and may be associated with nausea and vomiting. Appetite is normally reduced and the symptoms are persistent and severe.

Left untreated, peptic and duodenal ulcers can cause internal bleeding and can eat a hole through the wall of your stomach or small intestine. This can lead to serious infection of the abdominal cavity (peritonitis). People with peptic or duodenal ulcers may suffer from anaemia due to loss of large amounts of blood over a long period. Peptic and duodenal ulcers can also produce scar tissue that can obstruct passage of food through the digestive tract, causing a reduction in appetite, vomiting and loss of weight. Infection with H pylori and stomach ulceration also increases the risk of stomach cancer.


This is an inflammation of the stomach lining and occurs if there are repeated bouts of indigestion, the causes of which have already been described.

When to seek medical advice

Frequent severe indigestion may indicate a more serious disease. See your doctor if you experience any of the following signs or symptoms:

  • Indigestion several times a week
  • Indigestion that returns soon after your antacid wears off
  • Indigestion that wakes you up at night
  • Use of H2 antagonist preparations for longer than two weeks
  • Persistent or recurrent abdominal pain
  • Vomiting, especially blood in your vomit
  • Unexplained weight loss
  • Persistent loss of appetite
  • Bloody (dark and black) stools
  • Indigestion accompanied by shortness of breath, sweating, or pain radiating to your chest, neck or arm (possible angina or heart attack)

Be sure to tell your doctor about any worsening signs or symptoms. If you have received a diagnosis of non-ulcer stomach pain, periodic evaluations may assure you and your doctor that no new serious disease has developed.


The symptoms of occasional indigestion respond well to treatments which are available over-the-counter. Many over-the-counter preparations are not suitable for those who are pregnant or for children under two years of age and may not be suitable for other individuals, so it is always important to talk to your pharmacist when buying preparation for indigestion over-the-counter.

The treatments available may contain more than one ingredient but are formulated as either liquids or tablets.


These are alkaline salts which neutralize the acid in the stomach and can be very effective in controlling the symptoms of indigestion.

Many people find tablet preparations more convenient as they can be carried about in pockets or bags, but wherever possible it is best to use a liquid preparation as they are more effective antacids.

Antacids are best taken about an hour after meals, because the emptying of the stomach has then slowed and the antacid will therefore remain in the stomach for longer.

Antacids may affect the body’s absorption of many drugs, including some antibiotics, anti-fungals, tablets with special coatings (for example those used in inflammatory bowel conditions and some types of aspirin), iron and lithium. If antacids are taken at different times to these drugs no problem will arise but it is important to discuss any medication you may be on with your pharmacist before buying antacid preparations. If there is a possible problem your pharmacist will be able to advise you of the best way to take your medication and antacids.

Examples are:-

Sodium Bicarbonate

This is a short-acting and effective neutralizer of acid and is most often available with other longer-acting antacids. Any antacids containing sodium should not be taken by people whose sodium intake has to be kept to a minimum (i.e. in people with high blood pressure or pregnant women especially those whose blood pressure is rising with pregnancy). Because of long-term side-effects antacids containing sodium bicarbonate are most suitable for short-term or occasional use.

Aluminium and magnesium salts (e.g. aluminium hydroxide, magnesium trisilicate)

Aluminium-based antacids are effective neutralizers of acid but tend to be constipating. This can be useful if someone is suffering from a stomach-bug and has diarrhoea but is not useful when used in someone with indigestion who may already be slightly constipated (e.g. in the elderly).

Magnesium-based antacids are also effective neutralizers of acid but have the tendency to cause diarrhoea. This can be useful if someone is suffering from indigestion and is also slightly constipated. However, when magnesium and aluminium salts are used in combination they cause little bowel disturbance and therefore these preparations are very effective and have few side-effects when used in indigestion.

Calcium Carbonate

This is an effective neutralizer of acid which acts quickly and has a long period of effectiveness. However, if taken on a regular basis it can cause the stomach to produce more acid. This and other side-effects with long-term use make the product most suitable for short-term or occasional use.

H2 antagonists (e.g. ranitidine and famotidine)

These reduce the amount of acid the stomach produces and are the most effective preparations available for use in heartburn and indigestion. They are available as tablets and some preparations also contain an antacid.

When food is known to make symptoms of heartburn worse these preparations are best taken before food.

H2 antagonists should not be used for longer than two weeks for the symptoms of heartburn or indigestion.

Dimethicone or simethicone

This reduces symptoms or belching and flatulence that may be associated with indigestion. It acts by breaking large air bubbles in the stomach and intestine into smaller air bubbles.

Brand name of preparations available and their ingredients


Rennie Rap-Eze chewable tablets

Remegel chewy tablets contain calcium carbonate

Bisodol chewable tablets contain calcium carbonate, light magnesium carbonate and sodium bicarbonate

Bisodol powder contains sodium bicarbonate, light magnesium carbonate and heavy magnesium carbonate.

Andrews Antacid

Rennie chewable tablets both contain calcium carbonate and heavy magnesium carbonate.

Maalox tablets and liquid contain aluminium hydroxide and magnesium hydroxide. Maalox plus tablets and liquid contain the same ingredients with the additional ingredient of simethicone, which is a surfactant and aids the breakdown of air bubbles in the intestines, so is useful when heartburn is accompanied by gas and wind.

All contain alkaline salts that neutralise excess acid in the stomach. They are effective for mild and occasional indigestion. Liquid preparations are always more effective than tablet ones in relieving heartburn or indigestion. None of the products cause drowsiness.


Pepcid AC tablets contain famotidine

Zantac tablets contain ranitidine

Pepcid Two tablets contain famotidine, calcium carbonate and magnesium hydroxide.

These reduce the acid production in the stomach and in Pepcid Two the addition of antacids also means acids in the stomach are neutralized. They are the most effective preparation for heartburn or indigestion and can be used in occasional indigestion where the use of antacids or antacids with alginates has not been effective. They do not cause drowsiness.


Rennie Deflatine tablets contain simethicone which reduces symptoms or belching and flatulence that may be associated with indigestion. It does not cause drowsiness.

Prevention and Self-Care

Eat smaller meals more regularly

Avoid missing meals as having an empty stomach can sometimes cause nausea or result in signs and symptoms similar to those of non-ulcer indigestion. Try eating smaller meals more frequently or take a small snack, such as a cracker or a piece of fruit. Avoid large meals and overeating which causes indigestion and may result in the gaining or excess weight, which increases risk of heartburn and indigestion.

Eliminate indigestion triggers

Some foods may trigger the signs and symptoms of non-ulcer indigestion, such as fatty and spicy foods, carbonated beverages, caffeine and alcohol; try not to avoid eating such foods. Avoid consuming more than three caffeinated drinks a day (tea, coffee and coca-cola).

Aid digestion

Set aside adequate time and sit down for meals, rushing to eat and eating whilst “on the run” can cause indigestion. When eating chew your food slowly and thoroughly. Wait to exercise for at least one hour, or to lie down for at least two hours after eating.

Reduce stress and increase rest

Identify current stress factors in your life. Try to manage your stress by exercising and listening to soothing music and consider taking up a relaxation technique such as yoga or meditation.

Aim for at least thirty to sixty minutes of physical activity on most days of the week to achieve and maintain a healthy weight, but try to balance activity with adequate rest. Try to get adequate sleep, avoiding late nights and very early awakenings, if possible have a set sleeping routine.

Stop smoking

Smoking may increase stomach acid. The swallowing of air during smoking may also aggravate belching and indigestion. In addition, smoking and alcohol increase your risk of stomach cancer. (link smoking cessation)

Avoid use of anti-inflammatory medication or take with care

The side effects common to all non-steroidal anti-inflammatory drugs are indigestion, nausea and occasionally vomiting. This occurs because they disrupt the protective barrier of the lining of the stomach and may produce ulcers, which can then lead to internal bleeding. Even though they can all produce this side effect some are more likely to do so than others. When the use of the non-steroidal anti-inflammatory drugs is stopped, these symptoms will disappear because the mucous barrier of the stomach lining is no longer being affected.

Because they may irritate the stomach it is important that they should always be taken with food, ideally a meal, but if not a generous snack.

Anti-inflammatories prescribed by the doctor should not be stopped without discussing this with the doctor concerned. The regular use of anti-inflammatories bought over-the-counter (e.g. aspirin or ibuprofen) should be avoided and the advice of a pharmacist sought for alternative pain relief.