What it is (overview)

An Abdomen Ultrasound Scan (USS)—often called an abdominal ultrasound—is a non-invasive diagnostic imaging test that uses high-frequency sound waves to produce real-time pictures of the organs and blood vessels inside your abdomen. It does not use radiation (unlike X-rays or CT scans). A handheld device called a transducer is moved over your skin with gel, and the returning sound waves are converted into images.

This test is commonly used for organ assessment of the liver, gallbladder and bile ducts, kidneys and urinary tract, pancreas, spleen, major blood vessels (like the aorta), and sometimes the bladder and prostate/uterus depending on the clinical question. It can help evaluate abdominal pain, swelling, abnormal blood tests, or concerns found on a physical exam.

What it “measures”: An abdominal USS does not measure blood levels like a lab test. Instead, it assesses the size, shape, and structure of abdominal organs, and looks for changes such as inflammation, fluid, stones, cysts, masses/tumors, blockage (obstruction), or altered blood flow when Doppler ultrasound is used.

What results may mean (in plain language): A “normal” result usually means the organs seen have a typical appearance and no obvious cause of symptoms is visible on ultrasound. An “abnormal” result could show findings such as fatty changes in the liver (fatty liver), gallstones, kidney stones, cysts (fluid-filled sacs), enlarged organs, signs of infection or inflammation, blocked bile ducts, or a mass that may need further testing. Ultrasound findings are interpreted along with your symptoms, medical history, and other tests (for example liver function tests, kidney function tests, urine tests, or CT/MRI if needed).

When & why it's usually done

Doctors commonly order an abdominal ultrasound (USS) to investigate symptoms, check organ health, or monitor known conditions. It is often chosen first because it is widely available, painless, and a non-invasive test that can quickly provide useful information.

Typical reasons include:

• Abdominal pain (especially upper right abdominal pain that may suggest gallbladder or liver issues)
• Nausea, vomiting, indigestion, or bloating when gallbladder, liver, or pancreatic disease is suspected
• Jaundice (yellowing of skin/eyes) or suspected bile duct blockage
• Abnormal liver blood tests or concerns about liver health (e.g., fatty liver disease)
• Blood in the urine, flank pain, recurrent urinary infections, or concerns about kidney function
• Suspected gallstones, kidney stones, or urinary tract obstruction
• A palpable lump, abdominal swelling, or suspected ascites (fluid in the abdomen)
• Follow-up of known cysts, masses, or prior imaging findings
• Monitoring chronic conditions (e.g., fatty liver, chronic kidney disease), or checking for complications
• Assessment of major abdominal blood vessels, such as screening or follow-up of an abdominal aortic aneurysm in appropriate patients

An abdominal ultrasound may also be used to guide procedures (such as draining fluid or taking a biopsy) because it allows real-time visualization.

Common diseases related to it

• Gallstones (cholelithiasis) and gallbladder inflammation (cholecystitis)
• Fatty liver disease (including metabolic dysfunction–associated steatotic liver disease)
• Hepatitis (inflammation of the liver) and signs of chronic liver disease/cirrhosis
• Bile duct obstruction and dilated bile ducts (e.g., from stones or strictures)
• Kidney stones (renal calculi) and urinary tract obstruction (hydronephrosis)
• Kidney cysts and polycystic kidney disease (suspected/monitoring)
• Kidney infections (pyelonephritis—supportive findings in some cases)
• Pancreatitis (ultrasound may help identify gallstone-related causes; pancreas visibility can vary)
• Liver cysts, hemangiomas, and other benign liver lesions
• Suspicious abdominal masses/tumors (requires further characterization)
• Ascites (fluid in the abdomen)
• Splenomegaly (enlarged spleen)
• Abdominal aortic aneurysm (AAA)

Health goals where it may help

• Supporting liver health by assessing fatty liver changes, liver size, and structural concerns
• Gallbladder assessment for people with recurrent upper abdominal pain or suspected gallstones
• Monitoring kidney function and kidney health by checking for obstruction, stones, or cysts that may affect drainage
• Evaluating unexplained abdominal pain with a safe, radiation-free imaging option
• Tracking known conditions (e.g., fatty liver disease, cysts, or previously identified lesions) over time
• Screening and monitoring abdominal blood vessels (e.g., AAA in appropriate risk groups)
• Checking for fluid retention (ascites) in people with liver, heart, or other chronic conditions
• Guiding treatment decisions by helping clinicians decide whether further tests (bloodwork, CT/MRI, endoscopy) are needed