Murphy's sign is a medical term used to describe a patient's specific reaction when an abdominal examination is performed. It occurs when the person stops breathing for a period of time in response to pain caused by palpation of a swollen gallbladder. Assessing for a positive Murphy's sign is performed by doctors and other medical professionals to determine whether a patient is suffering from cholecystitis, an inflamed gallbladder, rather than another intestinal condition that would not produce a positive reaction. This term may also refer to a finding during a sonogram examination in which a patient experiences pain when the sonographic device is pressed over the gallbladder.

In order to test for a positive Murphy's sign, the affected patient first lies down on his or her back either with clothing removed or raised above the chest area. The patient breathes out while the doctor places his or her hand on the lower ribs, between the 7th and 10th ribs, at the midpoint of the chest. As the doctor continues to feel the area, he or she will ask the patient to breathe slowly. If the patient reacts by holding his or her breath, or has difficulty breathing in, the test is positive. Breathing difficulty is caused by acute pain when the diaphragm pushes down on the affected gallbladder.

Cholecystitis is indicated by a positive sign. A negative sign requires further medical investigation and may indicate other conditions, such as ascending cholangitis or pyelonephritis. Ascending cholangitis is a bacterial infection of the bile duct, while pyelonephritis is a type of kidney infection. It is very important that the examiner's hand is placed accurately on the patient's body, or an inaccurate diagnosis may result. The test is only positive if the pain is on the left side of the body and not the right, so both sides must be tested for accuracy.

Using ultrasound technology, technicians can accurately locate a patient's gallbladder with high resolution imagery. The term Murphy's sign is also used in ultrasonography but is distinct from the result of the physical examination. For a positive sign to occur during an ultrasound exam, the patient must demonstrate pain when the sonogram wand is placed directly over the site of the organ, but not in any other area. This may also indicate cholecystitis and is often used in conjunction with the physical examination in diagnostic testing. A sonographic Murphy's sign tends to be more accurate when the presence of gallstones exists.