Definition

Acute cholecystitis is acute inflammation of the gallbladder, most often caused by a stone or sludge obstructing the cystic duct. Acalculous cholecystitis occurs without stones, particularly in critically ill patients, and can be equally serious.

Epidemiology

Gallstones are common in adults and many remain asymptomatic. Acute cholecystitis is a frequent upper-GI surgical admission, usually after persistent cystic-duct obstruction, while acalculous disease is more associated with critical illness, postoperative states and major systemic stress.

Pathophysiology

Persistent cystic-duct obstruction traps bile and raises gallbladder pressure. Wall oedema, inflammation and reduced perfusion develop, with secondary infection in some patients. Continued inflammation can cause empyema, gangrene, perforation or abscess. Acalculous disease results from stasis and ischaemia without a gallstone.

First principles

Persistent obstruction makes the gallbladder inflamed

A stone or sludge that remains impacted at the cystic duct or gallbladder neck prevents drainage. Distension, wall oedema and local inflammation follow; secondary infection may occur. This produces constant right-upper-quadrant pain and systemic features rather than the short-lived, self-limiting pain of biliary colic.^1,2

The cystic duct and common bile duct are different pathways

Acute cholecystitis is primarily a gallbladder and cystic-duct problem. Jaundice, a cholestatic liver-test pattern or a dilated common bile duct raises concern for a second problem such as a common-bile-duct stone, which needs MRCP or EUS and a bile-duct-clearance pathway rather than assuming uncomplicated cholecystitis.¹

Ultrasound and liver tests guide the next branch

NICE recommends liver-function tests and ultrasound for suspected gallstone disease. Ultrasound assesses gallstones and gallbladder inflammation, while liver tests help identify patients who need further common-bile-duct imaging. No single sign, laboratory result or ultrasound feature should replace the overall clinical assessment.¹

Source control prevents recurrent and progressive disease

Supportive treatment and antibiotics may control the acute inflammatory or infective episode, but they do not remove the gallbladder source. NICE recommends early laparoscopic cholecystectomy within one week of diagnosis; drainage is reserved for selected patients in whom surgery is contraindicated or not an option.^1,2,3

Presentation

Persistent right-upper-quadrant or epigastric pain with tenderness or a positive Murphy sign, nausea or vomiting and systemic inflammation. Jaundice, shock, peritonism or rapid deterioration suggests duct obstruction, sepsis or a complication rather than uncomplicated cholecystitis.^1,2

Cardinal features

Constant right-upper-quadrant or epigastric pain
Right-upper-quadrant tenderness or a positive Murphy sign
Fever, tachycardia or other systemic inflammatory features
Nausea, vomiting and anorexia
Gallstones or gallbladder inflammatory changes on ultrasound
Raised inflammatory markers, with liver tests helping identify duct involvement

Red flags

Hypotension, confusion, raised lactate or organ dysfunction suggesting sepsis
Generalised peritonism, severe local tenderness or sudden deterioration suggesting gangrene or perforation
Jaundice, a markedly cholestatic liver-test pattern or a dilated common bile duct
Persistent fever or pain despite initial treatment, suggesting empyema, gangrene, abscess or uncontrolled source
Critically ill, postoperative or immunocompromised patient with possible acalculous cholecystitis
Gas in the gallbladder wall or lumen, especially in a patient with diabetes, suggesting emphysematous disease

Investigations

Liver-function tests and inflammatory blood tests

Check liver tests and inflammatory markers alongside FBC, renal function, electrolytes, glucose and lactate when clinically indicated. The pattern helps separate isolated gallbladder inflammation from common-bile-duct obstruction and identifies systemic illness requiring escalation.

Expected finding: Inflammatory markers may be raised in acute cholecystitis. Normal or mildly abnormal liver tests support an isolated gallbladder process; marked cholestatic abnormality or jaundice raises concern for common-bile-duct disease.

^1,4

Transabdominal ultrasound

Use ultrasound first line to identify gallstones and signs of acute gallbladder pathology and to assess the bile duct. Interpret gallbladder wall, distension, pericholecystic fluid, an impacted neck stone and sonographic tenderness together with the clinical picture.

Expected finding: Gallstones with gallbladder distension, wall inflammation, pericholecystic fluid or sonographic Murphy sign may support acute cholecystitis. A dilated common bile duct or visible duct stone changes the pathway.

^1,2

MRCP or endoscopic ultrasound for suspected common-bile-duct stone

If ultrasound has not detected a duct stone but the bile duct is dilated or liver tests are abnormal, consider MRCP. If MRCP is non-diagnostic, consider EUS. Do not use an isolated gallbladder diagnosis to ignore jaundice or cholestasis.

Expected finding: A duct stone, obstruction or alternative biliary lesion may be demonstrated. Positive findings require bile-duct clearance planning, usually with ERCP before or at the time of cholecystectomy or surgical clearance.

¹

Sepsis and operative-risk assessment

Use ABCDE, observations, urine output, lactate and organ-function assessment when the patient is systemically unwell. Obtain ECG, group and save/crossmatch and other pre-operative tests according to the clinical and anaesthetic risk, without delaying source control unnecessarily.

Expected finding: Sepsis, shock, renal dysfunction, coagulopathy or severe comorbidity determines escalation, antibiotic route, anaesthetic planning and whether drainage or surgery is currently safe.

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Management

Step	Detail	Source
Stabilise, relieve symptoms and assess for sepsis	Use ABCDE, give appropriate IV fluids for hypovolaemia, analgesia and antiemetic treatment, and keep the patient nil by mouth while surgical assessment is underway. Monitor observations, urine output and organ function. Use current BNF and local protocols for drug choice, dose, renal adjustment and contraindications.^1,2,4,5,6	NICE CG188, NICE HTG617 and current BNF monographs
Give antimicrobial treatment when infection or sepsis is suspected	Start empirical antimicrobial treatment when clinically indicated by acute infection, sepsis, complicated disease or the local surgical pathway. Choose the regimen, route, renal adjustment and duration from the current local antimicrobial policy and BNF; review after source control, microbiology and clinical response rather than continuing broad treatment automatically.^2,4,7,8,9	NICE HTG617, NICE NG253 and current BNF antimicrobial monographs
Arrange early laparoscopic cholecystectomy	Offer laparoscopic cholecystectomy within one week of diagnosis. Early surgery provides definitive source control and avoids the recurrent attacks and complications associated with waiting for the acute episode to settle. Involve the senior upper-GI surgical and anaesthetic teams early when disease is severe or the operative risk is high.^1,10	NICE CG188 recommendation 1.2.4 and NICE QS104
Clear a suspected common-bile-duct stone through the correct pathway	If jaundice, cholestatic liver tests, a dilated duct or MRCP/EUS evidence suggests common-bile-duct stones, plan bile-duct clearance surgically at cholecystectomy or with ERCP before or at surgery. If ERCP cannot clear the duct, biliary stenting is a temporary drainage measure until definitive endoscopic or surgical clearance.¹	NICE CG188 recommendations 1.3.1 to 1.3.4
Use gallbladder drainage only when surgery is unsafe or unavailable	Offer percutaneous cholecystostomy for gallbladder empyema when surgery is contraindicated at presentation and conservative management is unsuccessful. Reconsider cholecystectomy once the patient is well enough. Endoscopic ultrasound-guided gallbladder drainage can be used when surgery is not an option only in a specialist service with appropriate governance, consent and audit.^1,2,3	NICE CG188 recommendations 1.2.5 to 1.2.6 and NICE HTG683
Escalate complications and provide safe follow-up	Generalised peritonitis, gangrene, perforation, abscess, emphysematous disease, uncontrolled sepsis or clinical deterioration needs urgent senior surgical and critical-care review. After recovery, explain wound and bile-duct follow-up, review histology and ensure symptomatic gallstones are not left untreated without a documented plan.^1,4,2	NICE CG188, NICE NG253 and NICE HTG617

Illustrations

Ultrasound features of acute cholecystitisGallbladder ultrasound demonstrating abnormal wall thickening, highlighted by arrows and calipers.James Heilman, MD, Wikimedia Commons · CC-BY-SA-3.0

Eliciting Murphy's signClinical illustration of the examination technique for Murphy's sign, showing palpation under the right costal margin during inspiration.PassFinals · original

Gangrenous acute cholecystitis on histologyHistological section of gallbladder wall showing sloughed mucosa, necrosis and dense neutrophilic inflammation in gangrenous acute cholecystitis.Mikael Häggström, M.D., Wikimedia Commons · CC0

Differentials

Biliary colic

Transient postprandial pain without persistent systemic inflammation or inflammatory gallbladder changes.

Ascending cholangitis

Systemic infection with jaundice or cholestatic obstruction from the common bile duct; requires urgent biliary drainage assessment.

Gallstone pancreatitis

Predominantly epigastric pain radiating to the back with compatible pancreatic enzyme and imaging findings.

Peptic ulcer disease or perforation

Epigastric pain, peritonism or free intraperitoneal gas rather than an isolated gallbladder process.

Right lower-lobe pneumonia or acute coronary syndrome

Referred upper-abdominal pain with respiratory, ECG or cardiac findings.

Liver abscess or hepatitis

Systemic illness or liver-test pattern and imaging findings that do not fit isolated cholecystitis.

Complications

Gallbladder empyema
Gangrene, perforation, abscess and biliary peritonitis
Emphysematous cholecystitis
Common-bile-duct obstruction and ascending cholangitis
Cholecystoenteric fistula and gallstone ileus
Recurrent biliary attacks and recurrent admissions
Sepsis, organ dysfunction and death

Prognosis

Most suitable patients recover with supportive treatment, appropriate antimicrobial therapy and early laparoscopic cholecystectomy. Complicated, acalculous and septic disease carries higher risk, and prognosis depends on rapid recognition, resuscitation, biliary assessment and definitive source control.

Guidelines

Gallstone disease: diagnosis and management (CG188) (NICE, 2014)
Endoscopic ultrasound-guided gallbladder drainage when surgery is not an option (HTG683) (NICE, 2023)

Acute Cholecystitis