Final answer:
The most common cause of acute gastritis is the repeated use of NSAIDs, such as aspirin or ibuprofen. Other causes include viral infections and radiation therapy.
Step-by-step explanation:
One of the most common causes of acute gastritis is the repeated use of NSAIDs (non-steroidal anti-inflammatory drugs). NSAIDs such as aspirin or ibuprofen can irritate the lining of the stomach and lead to inflammation. Other causes of acute gastritis include viral infections and radiation therapy.