For those trained in such touching, pressing on your abdomen can provide significant clues to potential problems.
The external examination with the hands gives doctors information about such important structures as the liver, spleen, kidneys, intestines, pancreas, bladder, gallbladder, appendix, abdominal aorta (the major blood vessel from your heart to your legs), and in females, the uterus and ovaries.
When the doctor presses on your abdomen, he or she is feeling to see if any of these are enlarged or tender, making them painful to touch, which could indicate disease.
Doctors use two different techniques to examine your abdomen: palpation and percussion.
A diagnosis is rarely made from only a manual examination of the abdomen, but this procedure can turn up what appear to be abnormalities, warranting further examination or testing.
Palpation means pushing down to see if the organs can be felt. For example, the aorta that supplies blood to the lower extremities runs directly beneath the navel and should be only an inch wide; if it is wider than that, there could be a problem such as an aneurysm.
The doctor also looks for tenderness, or pain that you experience when he depresses then quickly lifts his hands off your stomach (rebound tenderness). Such pain indicates that the peritoneum, or the membrane that lines the abdominal cavity, is inflamed -- as often happens when the appendix becomes diseased, the bowel is perforated or there is peritonitis.
Then there's the spleen. If you're a healthy adult, the doctor shouldn't be able to feel it. If he can, that means the spleen is enlarged. The next step is finding the reason for the enlargement -- possibly disease such as infectious mononucleosis or leukemia.
Percussion means tapping the abdomen and listening to the sounds. It's similar to the tapping done by shoppers who know a ripe watermelon sounds different from an unripe one. When the doctor taps below the rib cage, he can hear the sounds made by a normal liver. But when he taps beyond where the liver should extend, the same sound could indicate an enlarged liver. Fluid in the abdominal cavity (ascites), a result of heart, liver or kidney disease, can sometimes be detected by percussion.