What causes indigestion?
Causes of occasional indigestion can be simple. For example, many people get indigestion after an especially large or rich meal. That’s easy to explain: your digestive system is working harder than usual to accommodate a heavy load. Your stomach is stretching, your gallbladder and pancreas are contracting, and they’re all producing strong digestive juices, which may be irritating your tissues.
But indigestion that lasts longer than one meal, or that comes and goes chronically, is often less simple. There may be a variety of factors involved. Sometimes there’s an organic cause, like a disease. And sometimes there’s no obvious cause. This is called functional dyspepsia. Functional GI disorders occur when the nerves in your GI tract are hypersensitized, which lowers your threshold for discomfort.
In general, causes of indigestion fall into three categories:
- Your eating habits.
- How your digestive system is functioning.
- Your perception of pain and discomfort.
What is the main cause of indigestion?
When there’s an organic cause, it usually has to do with stomach acid. Acid causes the telltale burning sensation often described in indigestion. Your stomach has a strong lining designed to protect it from its own acid, but sometimes the lining is worn down. When this happens, it becomes irritated and inflamed by the acid. Inflammation of your stomach lining has other causes, but they’re less common.
Sometimes gastric juices escape from your stomach into the top part of your small intestine (duodenum). Your duodenum doesn’t have the same protective lining as your stomach, so acid can do more damage there. Acids can also escape from the top of your stomach into the bottom of your esophagus. This is called acid reflux. Your esophagus isn’t designed to tolerate acid, either.
Acid reflux may explain other symptoms that can come with indigestion, such as burping, regurgitation and heartburn. You can have acid reflux and discomfort in your esophagus even if your stomach lining is still intact. When acid eats away at your stomach lining, though, you have peptic ulcer disease, which can cause ulcers in your stomach and duodenum. Peptic ulcers also cause a burning kind of pain.
Peptic ulcer disease may explain other symptoms that can come with indigestion, such as early satiety (fullness), nausea and bloating. In fact, acid and ulcers are so often the organic causes of chronic indigestion that healthcare providers have come to refer to functional dyspepsia as “non-ulcer dyspepsia”. But overall, functional dyspepsia is more common than any organic cause of indigestion.
What are other possible causes?
Diet and lifestyle factors that may contribute to occasional dyspepsia include:
- Eating too much or too fast. Overeating stretches your stomach and makes it more likely for acid to escape through the top.
- Too much fat in your diet. High-fat content triggers more acids and enzymes, which may irritate your tissues.
- Unidentified food intolerances. You may be having difficulties digesting certain foods.
- Smoking and alcohol use. Both of these substances irritate the mucous lining throughout your GI tract. They can cause inflammation.
- Overuse of NSAIDs (like aspirin and ibuprofen). Too many NSAIDs can erode your stomach lining.
- Stress and anxiety. Your GI tract is intimately connected with your brain through nerves, and each can affect the other.
Diseases and conditions that may be involved in chronic dyspepsia include:
- Peptic ulcer disease.
- Gastroesophageal reflux disease.
- Hyperchlorhydria (too much stomach acid).
- Gastritis (inflammation of your stomach lining).
- Gastroparesis (slow stomach emptying).
- Hiatal hernia (your stomach pushes up through your diaphragm).
- Bacterial overgrowth (in your stomach or small intestine).
- Eating disorders.
- Gallstones.
- Gallbladder inflammation (cholecystitis).
- Pancreas inflammation (pancreatitis).
- Irritable bowel syndrome (IBS).
- Celiac disease.
- Small bowel obstruction.
- Stomach cancer.
- Visceral hypersensitivity.
