'Gastritis' means inflammation of the stomach lining. It is a common symptom with a wide range of causes.
The stomach lining ('mucosa') contains special cells that produce acid and enzymes that start to digest food.
The acid can potentially break down the stomach lining too, so other cells in the lining produce mucus to provide a slimy layer that protects it from this acid.
Gastritis happens when this defence barrier is damaged – by H. pylori bacteria or after excessive consumption of alcohol, for example (see What are the possible causes?).
For most people, gastritis isn't serious and improves quickly with treatment. But if it is left untreated, it can last for years.
Many people with gastritis don't have any symptoms – usually because they have a non-erosive form of the disease caused by a bacterial infection.
In other cases, gastritis can cause:
If the stomach lining has been worn away, it is classed as erosive gastritis. Damaged areas of stomach lining (unprotected by mucus) are exposed to stomach acid, which can cause pain and lead to stomach ulcers and bleeding.
If symptoms come on suddenly and severely, it is classed as acute gastritis. If it has lasted a long time (usually because of bacterial infection), it is chronic gastritis.
Gastritis is usually caused by one of the following:
Less commonly, gastritis can be caused by an autoimmune reaction – when the immune system mistakenly attacks the body's own cells and tissues (in this case, the stomach lining). This may happen if you already have another autoimmune condition, such as Hashimoto's thyroid disease or type 1 diabetes.
Many people become infected with H. pylori bacteria and don't realise it. These stomach infections are common and usually don't cause symptoms.
Sometimes, though, an H. pylori infection can cause recurring bouts of indigestion. The bacteria can cause inflammation of the stomach lining.
This sort of gastritis is more common in older age groups and is usually the cause of chronic (persistent) non-erosive cases.
An H. pylori stomach infection is usually lifelong, unless it is treated with H. pylori eradication therapy.
If you have indigestion and stomach pain, you can try treating this yourself with changes to your diet and lifestyle, or with a number of different over-the-counter medications, such as antacids.
See your doctor if:
To identify the underlying cause, your doctor may recommend you have one or more of the following tests:
Treatment aims to reduce the amount of acid in the stomach to relieve symptoms and allow the stomach lining to heal, and to tackle any underlying cause.
You may be able to treat gastritis yourself, depending on the cause.
If you've been diagnosed with an H. pylori infection, you'll need H. pylori eradication therapy – which is essentially taking a proton pump inhibitor and two antibiotics. Learn more about eradication therapy.
If you think the cause of your gastritis is repeated use of NSAID painkillers, try switching to a different painkiller that isn't in the NSAID class, such as paracetamol. You may want to talk to your doctor about this.
Ongoing (chronic) gastritis increases your risk of developing:
Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.