A gastroenterologist checks your liver through a combination of physical examination, blood tests, imaging, and sometimes more specialized procedures depending on what the initial results show. Most people start with bloodwork and an ultrasound, and only a fraction need advanced testing like a liver stiffness scan or biopsy. The process is typically layered: simple, noninvasive steps come first, and each result guides what happens next.
The Physical Exam
Before ordering any tests, your gastroenterologist will examine your abdomen by hand. They’ll ask you to lie on your back and press gently along your right side, starting below where the liver normally sits and working upward. As you take a deep breath, the liver moves downward and its edge passes under their fingertips. They’re feeling for size, tenderness, and texture. A healthy liver edge feels smooth and slightly firm. An edge that’s blunt, rounded, or irregular suggests something abnormal, like scarring or swelling.
They’ll also tap along your rib cage (a technique called percussion) to map the liver’s upper and lower borders. A normal liver spans about 6 to 12 centimeters along the midline of the right side of your chest. If it measures larger, that could point to inflammation, fatty buildup, or congestion. Some tenderness during the exam is normal, but significant pain suggests active inflammation like hepatitis.
Your doctor will also look for visible signs of liver trouble: yellowing of the skin or eyes, swelling in the abdomen, dark urine, pale stools, easy bruising, or prominent veins on the belly. These signs, along with symptoms like persistent fatigue, itching, nausea, or a feeling of fullness under the right ribs, often determine which tests come next.
Blood Tests for Liver Function
A liver panel is usually the first diagnostic step. This is a standard blood draw that measures several enzymes and proteins to reveal how well your liver is working and whether it’s been damaged.
The two most important enzyme markers are ALT and AST. ALT is found almost exclusively in the liver, making it a strong indicator of liver cell damage. Normal levels run between 7 and 55 units per liter. AST is similar but less specific, since it also exists in muscle tissue. Its normal range is 8 to 48 units per liter. When liver cells are injured, both enzymes leak into the bloodstream and levels rise.
The panel also checks alkaline phosphatase (ALP) and GGT, two enzymes that tend to spike when bile ducts are blocked or damaged rather than when liver cells themselves are injured. This distinction helps your doctor narrow down what type of liver problem might be occurring.
Albumin and total protein levels reveal how well the liver is producing the proteins your body needs. The liver makes albumin, which helps fight infection and carry substances through the blood. Low albumin often signals chronic liver damage. Bilirubin, the pigment that causes jaundice, rounds out the panel. It’s a byproduct of red blood cell breakdown that the liver normally processes and clears. When the liver can’t keep up, bilirubin accumulates and your skin and eyes turn yellow.
You may not need to fast before a liver panel, though your doctor might request fasting if they’re running additional metabolic tests at the same time. Follow whatever instructions you’re given for your specific appointment.
Ultrasound: The First Imaging Step
If blood tests come back abnormal, or if your symptoms and history warrant a closer look, an abdominal ultrasound is typically the next move. It’s painless, uses no radiation, and takes about 20 to 30 minutes. A technician presses a handheld probe against your abdomen, and sound waves create real-time images of your liver on a screen.
An ultrasound can reveal fat deposits in the liver (the hallmark of steatotic liver disease, formerly called fatty liver disease), signs of inflammation, scar tissue from fibrosis or cirrhosis, and growths such as cysts, hemangiomas, or tumors. The radiologist reading your images can often distinguish between a fluid-filled cyst and a solid mass based on how the sound waves bounce back. The scan also shows enlarged blood vessels or bile ducts, gallstones, and fluid accumulation in the abdomen.
Traditionally, patients are told to fast for six hours before an abdominal ultrasound. However, research has shown that a light breakfast a few hours before the scan doesn’t significantly affect image quality. Your clinic may still ask you to fast, particularly if the gallbladder also needs to be evaluated, since food causes the gallbladder to contract and become harder to image.
FibroScan: Measuring Liver Stiffness
If your doctor suspects scarring in the liver, they may order a FibroScan, a specialized ultrasound-based test that measures how stiff your liver tissue is. Scar tissue is harder than healthy tissue, so stiffness serves as a reliable stand-in for a biopsy in many cases.
During the test, a probe placed on your skin sends a gentle vibration into your liver. The device tracks how fast the resulting wave travels through the tissue. Faster waves mean stiffer, more scarred tissue. The result is reported in kilopascals (kPa), and the numbers map to stages of liver scarring:
- Below 7 kPa: Generally normal, minimal or no fibrosis
- 7.2 kPa and above: Suggests moderate fibrosis
- 12.5 kPa and above: Suggests severe fibrosis
- 17.6 kPa and above: Consistent with cirrhosis
The entire test takes about 10 minutes and feels like a mild thumping sensation against your side. It’s become a central tool in managing metabolic-associated steatotic liver disease (MASLD), the updated name for what was previously called nonalcoholic fatty liver disease. Current guidelines from the American Association for the Study of Liver Diseases use FibroScan readings (formally called VCTE) as a primary way to stage fibrosis and determine treatment eligibility, often replacing liver biopsy for that purpose.
Bile Duct Imaging: MRCP and ERCP
When the concern involves the bile ducts, the tubes that carry bile from the liver to the intestine, your gastroenterologist has two main tools. The choice between them depends on whether they need to just look or also intervene.
MRCP is an MRI-based scan that produces detailed 3D images of the bile ducts and pancreatic duct without any needles, sedation, or radiation. You lie in an MRI machine, and the scan captures cross-sectional images that can reveal blockages, stones, strictures, and tumors. It’s painless and carries essentially no risk. For purely diagnostic purposes, MRCP matches the accuracy of more invasive alternatives across a wide range of bile duct conditions.
ERCP is a more involved procedure reserved for situations where treatment is needed alongside diagnosis. A gastroenterologist passes a flexible scope through your mouth, down to where the bile duct empties into the small intestine. From there, they can inject dye, take X-rays, remove stones, place stents, or take tissue samples. ERCP requires sedation and carries a complication rate of 1% to 7%, including risks of bleeding, infection, and inflammation of the pancreas. Because of these risks, ERCP is now used almost exclusively when a therapeutic intervention is planned, not just for looking.
Upper Endoscopy for Liver Complications
If you’ve been diagnosed with cirrhosis, your gastroenterologist will likely recommend an upper endoscopy (EGD). This isn’t to look at the liver directly but to check for a dangerous complication: varices. When a scarred liver restricts blood flow, pressure builds in the veins around the esophagus and stomach, causing them to swell. These swollen veins can rupture and cause life-threatening bleeding.
Endoscopy is the gold standard for detecting varices. Multiple international guidelines recommend screening with an upper endoscopy at the time of a new cirrhosis diagnosis. During the procedure, you’re sedated while a thin, flexible camera is guided down your throat. If varices are found, the doctor can assess their size and risk of bleeding, and in some cases, treat them during the same procedure by banding them with small rubber rings to prevent rupture.
Liver Biopsy: When Other Tests Aren’t Enough
A liver biopsy, where a small sample of tissue is removed and examined under a microscope, used to be the default way to evaluate liver disease. It’s still considered the most definitive diagnostic tool, but noninvasive tests like FibroScan and advanced blood markers have replaced it for most patients. Current practice guidelines describe biopsy as “impractical and unnecessary” for the majority of people being evaluated for fatty liver disease and fibrosis.
When a biopsy is needed, the most common approach is percutaneous: a needle is inserted through the skin on your right side, guided by ultrasound, to collect a tissue cylinder about 15 millimeters long. You’ll be asked to hold your breath briefly while the sample is taken. Afterward, you’ll lie still for several hours while staff monitor your blood pressure and pulse. Most people go home the next day.
For patients who can’t safely undergo a percutaneous biopsy, perhaps because of blood clotting problems, significant fluid in the abdomen, or a very small, shrunken liver, the transjugular approach is an alternative. A catheter is threaded through a vein in the neck down to the liver’s blood vessels, and the sample is collected from inside the vein. This method avoids puncturing the liver capsule, which reduces the risk of bleeding in high-risk patients.
What Determines Which Tests You Get
Not everyone who sees a gastroenterologist for liver concerns goes through every test on this list. The process is guided by your symptoms, risk factors, and what each round of results shows. Someone with mildly elevated liver enzymes and obesity might get bloodwork, an ultrasound, and a FibroScan. Someone with jaundice and suspected bile duct obstruction might skip straight to MRCP. A person with newly diagnosed cirrhosis will likely get both a FibroScan and an upper endoscopy to screen for varices.
The overall approach is designed to start simple and get more invasive only when necessary. Most liver conditions can now be diagnosed and staged without ever needing a biopsy or a procedure that requires sedation. If your gastroenterologist does recommend a more advanced test, it’s because the simpler tools have raised a specific question that needs a more precise answer.