By definition gastritis is inflammation of the stomach lining (gastro = stomach, it is = inflammation). For years, I thought gastritis and reflux (GERD) were pretty much the same thing. Recently though, I've been reading more about gastritis and how it is similar but different than reflux. It is possible to have both reflux and gastritis but you can also have them separately.
A little bit of anatomy may help explain the difference between gastritis and GERD. Where the esophagus meets the stomach there's a sphincter (known as the lower esophageal or cardiac sphincter). This sphincter allows food into the stomach and helps to keep food from backwashing up into the esophagus. Some reflux is normal. When the acid irritates the lining of the esophagus the result is GERD. The symptoms of this are the classic heartburn symptoms as well as the less well known symptoms of chronic cough, voice changes, etc.
So, while GERD is related to irritation in the esophagus, gastritis is related to irritation in the stomach. Symptoms of gastritis include eating a few bites and feeling full, nausea, bloating, and/or lack of appetite. Gastritis can worsen to the point of causing an ulcer which has the additional symptoms of black/tarry stools and/or vomit.
Many of the causes of GERD are the same as the causes of gastritis including long term use of NSAIDs for pain relief, smoking, and excessive alcohol consumption. On the other hand, gastritis can also be caused by H Pylori infection and can happen short term after a viral illness.
The gold standard test for gastritis is to do an endoscopy but before completing this somewhat invasive test a doctor may prefer to do a stool or breath test for H Pylori infection or may do a medication trial.
Treatment for GERD and gastritis are also often very similar but may vary for gastritis depending on the cause. The first line treatment is to decrease the stomach acid using an anti-acid, H2 blocker or proton pump inhibitor. If a patient tests positive for H Pylori on the other hand, acid reduction may help the symptoms somewhat but anti-biotics are needed to get rid of the infection and are used along with a proton pump inhibitor.
The most important thing I learned from this new understanding is that if you have reflux like symptoms and your doctor treats you for it and you get better but maybe not as better as you expect or if you get better and then worse again while still on meds then you should go back to your doctor. You don't necessarily need an endoscopy early on in the treatment of your symptoms given than stool tests and medication trials can often give doctors similar information. Lastly, the more I learn, the more I realize that being a doctor is nowhere close to an exact science and requires a lot of educated guesswork. Work with your doctor to find out the best treatment for you.