In liver, gallbladder and imaging reports, the CBD medical abbreviation means common bile duct, the tube that carries bile from the liver and gallbladder into the small intestine. Outside those settings, CBD most often means cannabidiol, a compound from the cannabis plant, and in neurology it can mean corticobasal degeneration.
Since the same three letters cover such different ideas, context decides. An ultrasound line that gives a CBD size in millimeters is about the bile duct. A medication list that records CBD oil is about cannabidiol. A movement disorder clinic note is likely about the brain condition. This guide explains each meaning, starting with the one patients most often meet on a scan report.
At a glance
Stands for
Common bile duct (in liver and gallbladder notes)Other meanings
Cannabidiol; corticobasal degeneration; chronic beryllium diseaseSpecialty
Gastroenterology, radiology, surgery, neurology, pharmacyWhere you see it
Ultrasound and MRI reports, ERCP notes, medication listsRelated tests
Do not confuse with
CBC (complete blood count) and CBG (capillary blood glucose)
The CBD medical abbreviation in liver and gallbladder care
Bile is a digestive fluid made by the liver. It flows through small ducts that join into the common hepatic duct, which then meets the duct from the gallbladder. From that junction down, the tube is called the common bile duct. It passes behind the pancreas and empties into the upper small bowel, known as the duodenum, where bile helps break down fat.
Because so many problems can block this one channel, the CBD gets special attention on imaging. A blockage can back bile up into the liver, causing yellowing of the skin and eyes, dark urine, pale stools, pain or fever.
Reading a CBD measurement on an ultrasound
Imaging reports usually state the duct's width and whether anything is inside it.
Ultrasound report: "RUQ US: CBD dilated to 9 mm, no stones seen. Recommend MRCP." RUQ means right upper quadrant of the abdomen, US is ultrasound, dilated means wider than expected, and MRCP is a type of MRI that maps the bile ducts without needles or dye injections into the ducts.
In adults the duct is often described as about 6 mm or less across, though it can be somewhat wider in older adults and after gallbladder removal. Radiologists and labs use their own reference values, so the report's comment about whether the size is normal is the part to focus on.
Common bile duct problems you may see named
Several conditions show up next to CBD in reports and surgical notes.
| Term | Plain meaning |
|---|---|
| Choledocholithiasis | A gallstone sitting in the common bile duct |
| Cholangitis | Infection of the bile ducts, often behind a blockage |
| Stricture | A narrowed segment of duct |
| Biliary dilation | Widened ducts, usually from something downstream |
| Gallstone pancreatitis | Pancreas inflammation caused by a stone near the duct opening |
A stone in the duct is often removed with ERCP, a scope procedure through the mouth that reaches the duct opening.
Cannabidiol and corticobasal degeneration
Away from the liver, CBD has two very different meanings.
- Cannabidiol: a compound from the cannabis plant that does not cause the high linked with THC. A prescription form is approved by the FDA for certain rare seizure disorders, while many other products are sold as supplements. Clinicians record it on medication lists because it can interact with other medicines and affect liver tests.
- Corticobasal degeneration: a rare brain disease that causes stiffness, slowness and trouble controlling one limb, along with changes in thinking. It is related to other movement disorders, and you may see it near terms such as PD in neurology notes.
- Chronic beryllium disease: a lung condition from workplace exposure to beryllium dust, seen in occupational medicine.
Lookalike lab shorthand
CBD is easy to misread as other three letter terms that start with CB.
- CBC: complete blood count, a routine blood test.
- CBG: capillary blood glucose, a fingerstick sugar check.
- CBI: continuous bladder irrigation after some urology procedures.
For more condition shorthand in one place, the diagnosis abbreviations hub groups terms by body system.
Questions to ask about a CBD finding
If your report mentions the common bile duct, these questions can help clarify it.
- Is the duct width normal for my age and history?
- Was a stone or blockage seen, or is more imaging needed?
- Do my liver blood tests fit with the scan?
- If cannabidiol is on my medication list, could it affect any of my other medicines?
We explain what the letters mean, not what a result means for you. Your clinician or pharmacist can review your report and medication list in full.
Frequently asked questions
What does CBD mean on a liver ultrasound?
On a liver or gallbladder ultrasound, CBD means common bile duct. The report usually gives its width in millimeters and notes any stones or blockage.
What is a normal CBD size?
In adults it is often described as about 6 mm or less, and it can be larger with age or after gallbladder removal. The radiologist's comment on the report says whether a given size is expected.
Does CBD on my medication list mean cannabidiol?
Yes, on a medication or supplement list CBD almost always means cannabidiol. Clinicians track it because it can interact with some medicines.
What is a CBD stone?
It is a gallstone that has moved into the common bile duct, called choledocholithiasis. It can block bile flow and is often removed with an ERCP procedure.