Atrophic gastritis (AG) develops when the lining of the stomach has been inflamed for several years. The inflammation is most often the result of a bacterial infection caused by the H. pylori bacterium. The bacteria disrupt the barrier of mucus that protects your stomach lining from the acidic juices that help with digestion. The infection will gradually destroy the cells in your stomach lining if it’s not treated.
In some cases, AG occurs when the immune system mistakenly attacks the healthy cells in your stomach lining. This is known as autoimmune atrophic gastritis.
AG is often caused by the H. pylori bacterium. The bacterial infection most often occurs during childhood and gets worse over time if it isn’t treated.
Direct contact with the feces, vomit, or saliva of an infected person can spread AG from person to person. An AG infection can also result from eating food or drinking water that’s contaminated with the bacteria.
Autoimmune AG develops when your body produces antibodies that attack healthy stomach cells by mistake. Antibodies are proteins that help your body recognize and fight infections. They normally attack harmful substances such as bacteria and viruses. However, antibodies in people with autoimmune AG mistakenly target the stomach cells responsible for producing acidic juices that help with digestion.
Antibodies may also attack a substance known as intrinsic factor. Intrinsic factor is a protein released by stomach cells that helps absorb vitamin B-12. A lack of intrinsic factor can cause an illness called pernicious anemia. In this disease, a B-12 deficiency makes it difficult or impossible for your body to make enough healthy red blood cells.
You’re more likely to develop AG if you have an H. pylori infection. This type of infection is fairly common around the world. It is more prevalent in areas of poverty and overcrowding.
Autoimmune AG is quite rare, but people who have thyroid disorders or diabetes are more likely to have this condition. You’re also more at risk if you’re African-American or of northern European descent.
AG is more common in people who are of Hispanic or Asian descent.
Both AG and autoimmune AG can significantly increase your risk of stomach cancer.
Many cases of AG go undiagnosed because there are usually no symptoms. However, if an H. pylori infection is present, common symptoms include:
- stomach pain
- nausea and vomiting
- loss of appetite
- unexpected weight loss
- stomach ulcers
- iron deficiency anemia (a low level of healthy red blood cells)
Autoimmune AG may lead to a B-12 deficiency, which can cause symptoms of anemia, including:
- chest pain
- heart palpitations
- tinnitus (ringing in the ears)
A B-12 deficiency can also cause nerve damage, which can lead to:
- limb numbness and tingling
- unsteadiness when walking
- mental confusion
An AG diagnosis usually involves a combination of clinical observation and testing. During a physical exam, your doctor will check for stomach tenderness by lightly pressing on certain areas of your stomach. They’ll also look for signs of B-12 deficiency, such as paleness, rapid pulse, and neurological deficits.
Your doctor might order blood tests to check for:
- low levels of pepsinogen, a protein produced by the stomach cells
- high levels of gastrin, a hormone that stimulates the production of stomach acid
- low levels of B-12 (for people who may have autoimmune AG)
- antibodies that attack stomach cells and intrinsic factor (for people who may have autoimmune AG)
In some cases, your doctor may need to perform a biopsy. Your doctor will insert an endoscope, (a long, slender instrument with a light attachment) down your throat and into your stomach. They’ll then take a sample of tissue from your stomach to look for evidence of AG. The sample of stomach tissue can also indicate signs of an H. pylori infection.
Most people with AG will see an improvement in symptoms once the condition is treated.
Treatment usually focuses on eliminating the H. pylori infection with the use of antibiotics. Your doctor may also prescribe medications that reduce or neutralize stomach acid. A less acidic environment helps your stomach lining to heal.
People with autoimmune AG may also be treated with B-12 injections.
AG is difficult to prevent, but you can lower your risk of getting an H. pylori infection by practicing good hygiene. This includes washing your hands after using the bathroom and before and after handling food. Parents or caregivers of young children should make sure to wash their hands after handling soiled diapers or linens. Teach your children good hygiene practices to avoid the spread of bacteria.