Health libraryBack to health library
How your stomach works
The stomach is an essential component of the digestive tract, the series of organs that processes food and extracts its nutrients.
Take a bite of food and swallow. You're not likely to think about that food again. But what was a brief encounter for your mouth is just the beginning of a long journey for the food you swallowed. The next stop on that journey is the stomach.
Situated in the upper part of your belly, the stomach is a hollow, sacklike organ. The outside of the stomach is made up of muscles that contract to mash food. The inside contains glands that secrete acids to help break down food during digestion.
Digestion is the body's method of pulling nutrients out of food and transferring them to the bloodstream. Digestion begins when you chew and swallow. From there, it's your stomach's job to store the swallowed food and liquid and mix it up with digestive juices. About three hours after entering the stomach, the partially digested food is released into the small intestine.
While the stomach does absorb some of the food it's digesting, the vast majority of food nutrients are absorbed through the small intestine.
Heartburn happens when digestive juices rise into the lower esophagus, causing a burning sensation in the area around the breastbone. According to the American Gastroenterological Association, heartburn can often be managed by over-the-counter medications and dietary and lifestyle changes, such as avoiding large meals, coffee and alcohol. If symptoms continue or worsen despite these remedies, consult a doctor for further evaluation.
Stomach cancer takes many years to develop. Often, there aren't symptoms until the cancer is far advanced. Symptoms of stomach cancer can include:
- Unexplained weight loss and reduced appetite.
- Abdominal pain or discomfort.
- Fullness just below the chest bone after eating small amounts of food.
- Heartburn or indigestion.
- Nausea or vomiting.
- Abdominal swelling.
Stomach cancer is not as common in the United States as in other countries, though at one time it was a leading cause of U.S. cancer deaths, according to the American Cancer Society. Researchers believe the decline in stomach cancer rates may be related to increased refrigeration of foods and declines in the consumption of salty and smoked foods. The ACS estimates that more than 27,000 new cases of stomach cancer are diagnosed in the U.S. each year.