Normal Gallbladder Size in Adults
The normal gallbladder in adults measures approximately 7-10 cm in length and up to 3.5-4 cm in transverse diameter, with a wall thickness less than 3 mm. 1
Length Measurements
- The fully distended gallbladder typically ranges from 7 to 10 cm in length, representing the standard reference range used in clinical practice 2
- Gallbladder size is highly variable due to its functional nature, and measurements can exceed 10 cm, particularly with increasing age 3
- Gallbladders with maximal diameters below 3.5 cm are classified as micro-gallbladders 3
Transverse Diameter
- The transverse diameter should not exceed 5 cm under normal circumstances 1
- When the transverse diameter exceeds 5 cm, this may indicate cholecystitis or pathologic distension 1
- The normal gallbladder is highly variable in shape, axis, and location, ranging from the midline to the midaxillary line 1
Wall Thickness
- Normal gallbladder wall thickness is less than 3 mm when measured on the anterior wall between the lumen and hepatic parenchyma 1, 4
- Wall thickness greater than 3 mm is considered abnormal and suggests acute cholecystitis or other pathology 1, 4
- The wall should appear echogenic with a single layer on ultrasound 3
Volume Measurements
- Mean gallbladder volume in normal adults is approximately 242 ± 234 mL 5
- Volume calculations are reserved for special clinical situations and achieve best reproducibility using the ellipsoid formula 3
- Volume measurements are rarely helpful in routine emergency ultrasound practice 1
Factors Affecting Size
- Age increases gallbladder size, with larger dimensions expected in elderly patients 3
- Diabetes and obesity significantly increase both gallbladder volume and wall thickness 3
- Female sex is associated with slightly different measurements compared to males 5
Clinical Context
- The gallbladder is a highly functional organ with considerable normal variation in size and shape 1, 3
- Measurements should be interpreted in the clinical context rather than relying on absolute cutoffs alone 1
- Gross increases in size may indicate hydrops, while increased transverse diameter suggests cholecystitis 1
Common Pitfalls
- Do not diagnose pathology based solely on size measurements without considering wall thickness, pericholecystic fluid, and sonographic Murphy's sign 1
- Avoid measuring the gallbladder through bowel gas or when patient positioning limits adequate visualization 1
- Remember that the gallbladder may be completely surrounded by hepatic parenchyma in some patients, requiring intercostal scanning approaches 1