Q: I've been under a lot of stress lately, and my stomach is always churning. Could I have given myself an ulcer?
A: Doctors used to think that ulcers (sores on the inside lining of your stomach, small intestine, or esophagus) were caused by stomach acid, which does increase during times of stress, and may be causing your churning feeling. But we now know that the majority of ulcers are caused by a type of bacteria called H. pylori, which can trigger inflammation in the gut. It's estimated that 20 percent of the population carries H. pylori in their digestive tract, putting them at greater risk of an ulcer, though it's not clear how the bacteria are transmitted.