Gastritis is a general term for a group of conditions with one thing in common: inflammation of the lining of the stomach. The inflammation of gastritis is most often the result of infection with the same bacterium that causes most stomach ulcers. Regular use of certain pain relievers and drinking too much alcohol also can contribute to gastritis.

Gastritis may occur suddenly (acute gastritis), or appear slowly over time (chronic gastritis). In some cases, gastritis can lead to ulcers and an increased risk of stomach cancer. For most people, however, gastritis isn't serious and improves quickly with treatment.

The signs and symptoms of gastritis include:

• Gnawing or burning ache or pain (indigestion) in your upper abdomen that may become either worse or better with eating
• Nausea
• Vomiting
• A feeling of fullness in your upper abdomen after eating

Gastritis doesn't always cause signs and symptoms.

When to see a doctor

Nearly everyone has had a bout of indigestion and stomach irritation. Most cases of indigestion are short-lived and don't require medical care. See your doctor if you have signs and symptoms of gastritis for a week or longer. Tell your doctor if your stomach discomfort occurs after taking prescription or over-the-counter drugs, especially aspirin or other pain relievers.

If you are vomiting blood, have blood in your stools or have stools that appear black, see your doctor right away to determine the cause.

Gastritis is an inflammation of the stomach lining. Weaknesses or injury to the mucus-lined barrier that protects your stomach wall allows your digestive juices to damage and inflame your stomach lining. A number of diseases and conditions can increase your risk of gastritis, including Crohn's disease and sarcoidosis, a condition in which collections of inflammatory cells grow in the body.

Factors that increase your risk of gastritis include:

• Bacterial infection. Although infection with Helicobacter pylori is among the most common worldwide human infections, only some people with the infection develop gastritis or other upper gastrointestinal disorders. Doctors believe vulnerability to the bacterium could be inherited or could be caused by lifestyle choices, such as smoking and diet.
• Regular use of pain relievers. Common pain relievers — such as aspirin, ibuprofen (Advil, Motrin IB, others) and naproxen (Aleve, Anaprox) — can cause both acute gastritis and chronic gastritis. Using these pain relievers regularly or taking too much of these drugs may reduce a key substance that helps preserve the protective lining of your stomach.
• Older age. Older adults have an increased risk of gastritis because the stomach lining tends to thin with age and because older adults are more likely to have H. pylori infection or autoimmune disorders than younger people are.
• Excessive alcohol use. Alcohol can irritate and erode your stomach lining, which makes your stomach more vulnerable to digestive juices. Excessive alcohol use is more likely to cause acute gastritis.
• Stress. Severe stress due to major surgery, injury, burns or severe infections can cause acute gastritis.

• Your own body attacking cells in your stomach. Called autoimmune gastritis, this type of gastritis occurs when your body attacks the cells that make up your stomach lining. This reaction can wear away at your stomach's protective barrier.

  Autoimmune gastritis is more common in people with other autoimmune disorders, including Hashimoto's disease and type 1 diabetes. Autoimmune gastritis can also be associated with vitamin B-12 deficiency.

• Other diseases and conditions. Gastritis may be associated with other medical conditions, including HIV/AIDS, Crohn's disease and parasitic infections.

Left untreated, gastritis may lead to stomach ulcers and stomach bleeding. Rarely, some forms of chronic gastritis may increase your risk of stomach cancer, especially if you have extensive thinning of the stomach lining and changes in the lining's cells.

Tell your doctor if your signs and symptoms aren't improving despite treatment for gastritis.

Preventing H. pylori infection

It's not clear how H. pylori spreads, but there's some evidence that it could be transmitted from person to person or through contaminated food and water. You can take steps to protect yourself from infections, such as H. pylori, by frequently washing your hands with soap and water and by eating foods that have been cooked completely.

Although your doctor is likely to suspect gastritis after talking to you about your medical history and performing an exam, you may also have one or more of the following tests to pinpoint the exact cause.

• Tests for H. pylori. Your doctor may recommend tests to determine whether you have the bacterium H. pylori. Which type of test you undergo depends on your situation. H. pylori may be detected in a blood test, in a stool test or by a breath test.

  For the breath test, you drink a small glass of clear, tasteless liquid that contains radioactive carbon. H. pylori bacteria break down the test liquid in your stomach. Later, you blow into a bag, which is then sealed. If you're infected with H. pylori, your breath sample will contain the radioactive carbon.

• Using a scope to examine your upper digestive system (endoscopy). During endoscopy, your doctor passes a flexible tube equipped with a lens (endoscope) down your throat and into your esophagus, stomach and small intestine. Using the endoscope, your doctor looks for signs of inflammation.

  If a suspicious area is found, your doctor may remove small tissue samples (biopsy) for laboratory examination. A biopsy can also identify the presence of H. pylori in your stomach lining.

• X-ray of your upper digestive system. Sometimes called a barium swallow or upper gastrointestinal series, this series of X-rays creates images of your esophagus, stomach and small intestine to look for abnormalities. To make the ulcer more visible, you may swallow a white, metallic liquid (containing barium) that coats your digestive tract.

Treatment of gastritis depends on the specific cause. Acute gastritis caused by nonsteroidal anti-inflammatory drugs or alcohol may be relieved by stopping use of those substances.

Medications used to treat gastritis include:

• Antibiotic medications to kill H. pylori. For H. pylori in your digestive tract, your doctor may recommend a combination of antibiotics, such as clarithromycin (Biaxin) and amoxicillin (Amoxil, Augmentin, others) or metronidazole (Flagyl), to kill the bacterium. Be sure to take the full antibiotic prescription, usually for seven to 14 days.

• Medications that block acid production and promote healing. Proton pump inhibitors reduce acid by blocking the action of the parts of cells that produce acid. These drugs include the prescription and over-the-counter medications omeprazole (Prilosec), lansoprazole (Prevacid), rabeprazole (Aciphex), esomeprazole (Nexium), dexlansoprazole (Dexilant) and pantoprazole (Protonix).

  Long-term use of proton pump inhibitors, particularly at high doses, may increase your risk of hip, wrist and spine fractures. Ask your doctor whether a calcium supplement may reduce this risk.

• Medications to reduce acid production. Acid blockers — also called histamine (H-2) blockers — reduce the amount of acid released into your digestive tract, which relieves gastritis pain and encourages healing. Available by prescription or over-the-counter, acid blockers include famotidine (Pepcid), cimetidine (Tagamet HB) and nizatidine (Axid AR).
• Antacids that neutralize stomach acid. Your doctor may include an antacid in your drug regimen. Antacids neutralize existing stomach acid and can provide rapid pain relief. Side effects can include constipation or diarrhea, depending on the main ingredients.

You may find some relief from signs and symptoms if you:

• Eat smaller, more-frequent meals. If you experience frequent indigestion, eat smaller meals more often to help ease the effects of stomach acid.
• Avoid irritating foods. Avoid foods that irritate your stomach, especially those that are spicy, acidic, fried or fatty.
• Avoid alcohol. Alcohol can irritate the mucous lining of your stomach.
• Consider switching pain relievers. If you use pain relievers that increase your risk of gastritis, ask your doctor whether acetaminophen (Tylenol, others) may be an option for you. This medication is less likely to aggravate your stomach problem.

Start by making an appointment with your family doctor or a general practitioner. If your doctor suspects gastritis, you may be referred to a specialist in digestive disorders (gastroenterologist).

What you can do

• Be aware of pre-appointment restrictions. When you make the appointment, ask if there's anything you need to do in advance, such as restrict your diet.
• Write down symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
• Write down key personal information, including major stresses or recent life changes.
• Make a list of all medications, vitamins or supplements you're taking.
• Consider taking someone along. Someone who accompanies you may remember something that you missed or forgot.
• Write down questions to ask your doctor.

Preparing a list of questions will help you make the most of your time with your doctor. For gastritis, some basic questions to ask your doctor include:

• What is likely causing my symptoms or condition?
• Could any of my medications be causing my condition?
• What are other possible causes for my symptoms or condition?
• What tests do I need?
• Is my condition likely temporary or chronic?
• What is the best course of action?
• What are alternatives to the primary approach you're suggesting?
• I have other health conditions. How can I best manage them together?
• Are there restrictions that I need to follow?
• Should I see a specialist?
• Is there a generic alternative to the medicine you're prescribing?
• Are there brochures or other printed material I can take? What websites do you recommend?
• What will determine whether I should schedule a follow-up visit?

Don't hesitate to ask other questions.

What to expect from your doctor

Your doctor is likely to ask you a number of questions, including:

• What are your symptoms?
• How severe are your symptoms? Would you describe your stomach pain as mildly uncomfortable or burning?
• Have your symptoms been continuous or occasional?
• Does anything, such as eating certain foods, seem to worsen your symptoms?
• Does anything, such as eating certain foods or taking antacids, seem to improve your symptoms?
• Do you experience any nausea or vomiting?
• Have you recently lost weight?
• How often do you take pain relievers, such as aspirin, ibuprofen or naproxen?
• How often do you drink alcohol, and how much do you drink?
• How would you rate your stress level?
• Have you noticed any black stools or blood in your stool?
• Have you ever had an ulcer?

What you can do in the meantime

Before your appointment, avoid drinking alcohol and eating foods that seem to irritate your stomach, such as those that are spicy, acidic, fried or fatty. But talk to your doctor before stopping any prescription medications you're taking.