Gallbladder problems are typically diagnosed through a combination of physical examination, blood tests, and imaging, with abdominal ultrasound being the first and most common test ordered. The specific combination depends on whether your doctor suspects gallstones, inflammation, infection, or a functional problem with how your gallbladder empties.
What Happens During the Physical Exam
Your doctor will press on the upper right side of your abdomen, just below the rib cage, and ask you to take a deep breath. As you inhale, your diaphragm pushes your liver and gallbladder downward toward the doctor’s fingers. If your gallbladder is inflamed, this contact causes a sharp enough pain that you’ll involuntarily stop breathing in. This response is called a positive Murphy’s sign, and it’s one of the most reliable bedside indicators of acute gallbladder inflammation (cholecystitis).
Your doctor will also ask about the pattern of your pain: whether it comes after eating fatty meals, how long episodes last, and whether the pain radiates to your right shoulder or back. These details help distinguish gallbladder problems from other causes of upper abdominal pain, including kidney stones, stomach ulcers, and inflammation of the upper intestine.
Blood Tests and What They Reveal
Blood work won’t diagnose gallstones directly, but it can show whether a stone is blocking your bile ducts or whether infection has set in. The key markers your doctor looks for include bilirubin, alkaline phosphatase, and liver enzymes.
Bilirubin is a waste product that normally flows out through bile. When a gallstone blocks the bile duct, bilirubin backs up into your blood, and the direct bilirubin level rises. This is often what’s behind the yellowing of the skin and eyes (jaundice) that some people notice. Alkaline phosphatase, an enzyme concentrated along the bile drainage system inside the liver, becomes markedly elevated when bile flow is obstructed. Liver enzymes (ALT and AST) tend to rise only moderately with a blockage, but they can spike significantly if infection develops in the bile ducts.
A complete blood count is also standard. A high white blood cell count points toward active infection or inflammation, which helps your doctor decide how urgently you need treatment.
Abdominal Ultrasound: The First-Line Test
An abdominal ultrasound is almost always the first imaging test for suspected gallbladder disease. It’s quick, painless, widely available, and doesn’t involve radiation. The ultrasound can detect gallstones, measure the gallbladder wall, and identify fluid collecting around the organ.
A normal gallbladder wall is thin. When it measures more than 3.5 millimeters, that’s a highly accurate sign of disease, though a normal-thickness wall doesn’t completely rule out inflammation. The sonographer will also look for pericholecystic fluid, a thin layer of liquid surrounding the gallbladder that signals acute inflammation. For gallstones specifically, ultrasound is excellent: stones show up as bright spots that cast a shadow behind them.
You’ll need to fast for six hours before the scan. This keeps the gallbladder full of bile so it’s easier to see clearly and reduces gas in the intestines that can interfere with the image. You can usually drink small amounts of clear fluids up to two hours beforehand.
HIDA Scan for Functional Problems
Sometimes ultrasound looks normal, but you’re still having classic gallbladder symptoms after meals. In that case, your doctor may order a HIDA scan (also called cholescintigraphy), which tests how well your gallbladder actually functions.
During the test, a small amount of radioactive tracer is injected into a vein. The tracer travels through your bloodstream to the liver, where it’s taken up and secreted into bile, just as your body handles bile naturally. A camera tracks the tracer as it flows from the liver into the gallbladder and then out through the bile ducts. Partway through, you’ll receive a hormone injection that triggers your gallbladder to contract and empty.
The key measurement is the gallbladder ejection fraction: what percentage of its contents the gallbladder squeezes out. A normal ejection fraction is above 30% to 35%. If yours falls below that threshold, it suggests biliary dyskinesia, a condition where the gallbladder doesn’t empty properly. A HIDA scan can also reveal a blocked cystic duct if the tracer never enters the gallbladder at all, which is a hallmark of acute cholecystitis.
MRCP and ERCP for Bile Duct Problems
When stones are suspected in the common bile duct rather than just in the gallbladder itself, more detailed imaging of the ductal system is needed. Two options exist, and they serve very different purposes.
MRCP (magnetic resonance cholangiopancreatography) is a specialized MRI that creates detailed images of the bile ducts and pancreatic duct without any needles, scopes, or contrast injections into the ducts. It’s purely diagnostic and has largely replaced the older, more invasive approach for the initial evaluation of suspected bile duct stones.
ERCP (endoscopic retrograde cholangiopancreatography) involves threading a thin, flexible scope through your mouth, down through the stomach, and into the upper intestine where the bile duct opens. Contrast dye is injected directly into the ducts and X-rays are taken. The major advantage of ERCP is that it’s both diagnostic and therapeutic: if a stone is found in the duct, the doctor can often remove it during the same procedure. Because ERCP carries a small risk of complications, including inflammation of the pancreas, it’s now generally reserved for situations where treatment during the procedure is expected rather than used as a first-line diagnostic test.
CT Scans and Their Role
CT scans are not the best tool for finding gallstones, since many stones don’t contain enough calcium to show up on a scan. However, CT is useful when the clinical picture is unclear and your doctor needs to rule out other causes of abdominal pain, such as appendicitis, pancreatitis, or a bowel obstruction. It can also detect complications of gallbladder disease, like a perforation or abscess, and is often the test performed in the emergency room when someone arrives with severe abdominal pain and the diagnosis isn’t yet obvious.
Monitoring Gallbladder Polyps
Gallbladder polyps are sometimes discovered incidentally during an ultrasound done for another reason. Most are harmless, but size matters. European guidelines recommend a surgical consultation for any polyp larger than 1 centimeter. Polyps between 6 and 9 millimeters warrant closer attention if certain risk factors are present, including age over 60 or a history of primary sclerosing cholangitis. Smaller polyps are typically monitored with repeat ultrasounds at regular intervals to check for growth.
Conditions That Mimic Gallbladder Pain
Part of the diagnostic process is ruling out other problems that cause similar symptoms. Pain in the right upper abdomen can come from a kidney infection or kidney stone, inflammation of the duodenum (the first segment of the small intestine), or even a bowel obstruction. In women, a less common condition called Fitz-Hugh-Curtis syndrome, an inflammation of the liver capsule related to pelvic infection, can closely mimic gallbladder pain. Peptic ulcers and pancreatitis are also frequent considerations. This overlap is exactly why doctors rarely rely on symptoms alone and move to blood tests and imaging to pin down the diagnosis.