Think rush hour traffic or grueling deadlines cause stomach ulcers? Think again.

“Stress won't cause stomach ulcers, but it can make them worse,” says Dr. David Graham, professor of medicine and molecular virology and microbiology at Baylor College of Medicine. “Stress causes the body to produce higher amounts of acid, which can irritate preexisting ulcers.”

According to Graham, a stomach ulcer is like a scraped knee -- if left alone, it will heal naturally. However, increased acid secretion caused by stress interrupts the healing process.

So if stress doesn't cause stomach ulcers, what does?

“H. pylori infection is the primary cause of stomach ulcers,” says Graham, also chief of gastroenterology at BCM, and chief of the digestive diseases section at the Michael E. DeBakey Veterans Affairs Medical Center . “This bacteria penetrates the stomach lining, eventually causing an ulcer.”

Although H. pylori infection is highly transmissible, it is not spread through kissing or sexual contact. Crowded living conditions, especially in areas of poor sanitation, provoke transmission. Fortunately, the bacterial infection can be treated with antibiotics.

Nonsteroidal anti-inflammatory drugs or NSAIDs such as aspirin, can also cause stomach ulcers. The anti-inflammatory agents in NSAIDs hinder the stomach's defense against powerful stomach acid. Terminating the use of NSAIDs and taking antacids to control acid secretion will allow ulcers to heal.

“Improved sanitation has decreased the transmission of H. pylori-induced stomach ulcers,” says Graham. “However, the quantity and duration of NSAIDs consumption still place people at risk.”