What are gallstones?
The gallbladder is a small, pear-shaped organ tucked beneath the liver on the upper right side of the abdomen. Its job is to store bile — a yellow-green digestive fluid made by the liver — and release it into the small intestine after meals to help break down fats.
Gallstones are hard, solid deposits that form inside the gallbladder when the balance of substances in bile goes wrong. They range in size from a grain of sand to a golf ball, and a person can have one or several hundred at the same time.
Two main types
Around 80% of gallstones are cholesterol stones — formed when bile contains too much cholesterol relative to bile salts and lecithin, causing cholesterol to crystallise and clump together. The remaining 20% are pigment stones — smaller, darker deposits made mainly of bilirubin (a product of red blood cell breakdown), and associated with conditions such as liver cirrhosis (scarring of the liver) and haemolytic anaemia (a blood disorder where red cells break down too quickly).
Who gets them?
Gallstones are one of the most common digestive conditions in the UK. They are significantly more common in women than men, and risk increases with age. Medical students have long used the "5 Fs" as a quick-recall memory aid for the classic risk profile: Female, Forty, Fertile, Fat, and Fair. While no mnemonic captures the full picture, these factors do reflect real biological risk: oestrogen (a female sex hormone) raises cholesterol levels in bile and slows gallbladder emptying; pregnancy amplifies both effects; and excess body weight increases cholesterol output in bile.
Other important risk factors include a family history of gallstones, rapid weight loss, long-term fasting, and certain medications including HRT (hormone replacement therapy) and some contraceptive pills.
Most gallstones cause no symptoms
The majority of people with gallstones — around 80%1 — never experience any symptoms at all. These are called "silent" or asymptomatic gallstones, often discovered incidentally during an ultrasound or scan done for another reason. For most of these people, no treatment is needed.
The problems begin when a gallstone moves out of the gallbladder and gets wedged in one of the bile ducts — the small tubes connecting the gallbladder to the liver, small intestine, and pancreas. This triggers a cascade of possible complications depending on which duct is blocked and for how long.
What happens when they do cause symptoms
When a gallstone temporarily blocks the cystic duct (the tube leading out of the gallbladder), it causes biliary colic — a severe, cramping pain in the upper right abdomen or the centre of the abdomen, often radiating to the right shoulder or back. The pain typically comes on suddenly after a fatty meal, lasts 30 minutes to several hours, and then subsides as the stone moves back or passes through. Despite the word "colic", the pain is usually constant during the episode rather than coming in waves.
If the blockage persists, the gallbladder becomes inflamed — a condition called acute cholecystitis (infection and swelling of the gallbladder). This produces more prolonged pain with fever, nausea, and tenderness on pressing the upper right abdomen. Gallstones can also travel into the common bile duct (the main tube draining bile from the liver) — called choledocholithiasis — causing jaundice (yellowing of the skin and whites of the eyes), or into the pancreatic duct, triggering gallstone pancreatitis (inflammation of the pancreas).
- Bile
- A yellow-green digestive fluid made by the liver and stored in the gallbladder; released after meals to help digest fats.
- Biliary colic
- Severe, cramping upper abdominal pain caused by a gallstone temporarily blocking the cystic duct; typically lasting 30 minutes to several hours.
- Cholecystectomy
- Surgical removal of the gallbladder; most commonly performed as keyhole (laparoscopic) surgery under general anaesthetic.
- Acute cholecystitis
- Inflammation and infection of the gallbladder, usually caused by a gallstone blocking the cystic duct; causes persistent pain, fever, and tenderness.
- Cholelithiasis
- The medical term for the presence of gallstones inside the gallbladder.
- Choledocholithiasis
- Gallstones that have passed into the common bile duct (the main tube draining bile from the liver); can cause jaundice and cholangitis.
- ERCP
- Endoscopic Retrograde Cholangiopancreatography — a procedure combining a flexible camera (endoscope) with X-ray imaging to examine and treat problems in the bile and pancreatic ducts.
- Gallstone pancreatitis
- Inflammation of the pancreas triggered when a gallstone blocks the shared channel through which bile and pancreatic juices drain into the small intestine.
- Cholangitis
- Infection and inflammation of the bile ducts, usually caused by a blocked common bile duct; a potentially serious complication requiring urgent treatment.
- Jaundice
- Yellowing of the skin and whites of the eyes, caused by a build-up of bilirubin when bile cannot flow normally; a sign that the bile duct may be blocked.
Why does it matter?
The scale of gallstone disease makes it a significant public health issue — not because most cases are dangerous, but because the minority that do become symptomatic can escalate quickly. Gallstone pancreatitis is one of the leading causes of acute pancreatitis (sudden inflammation of the pancreas) in the UK, and cholangitis (bile duct infection) carries a meaningful mortality risk when not recognised and treated promptly.
Understanding the distinction between silent and symptomatic gallstones — and the factors that determine who crosses that line — is what this article is about. Most people with gallstones never need surgery. For those who do, the evidence now provides a clearer picture of when and why.
What your doctor might do
When gallstones are suspected — whether due to symptoms or as an incidental finding — assessment in UK practice typically follows a structured pathway.
- Charcot's triad — right upper abdominal pain + fever + jaundice (yellowing of skin/eyes): suggests acute cholangitis (bile duct infection), clinically recognised as time-sensitive — 111 and urgent GP services exist for this.
- Reynold's pentad — Charcot's triad plus low blood pressure and confusion: suggests severe cholangitis with septic shock — 999 exists for this.
- Severe, persistent abdominal pain with vomiting that is not settling may indicate acute pancreatitis or cholecystitis — both clinically recognised as requiring hospital assessment.
What the research shows
Gallstones are extremely common — affecting roughly 1 in 7 UK adults — but the majority cause no problems and require no treatment. The key distinction is between silent (asymptomatic) gallstones, where current evidence and NICE guidance support watchful waiting, and symptomatic gallstones, where laparoscopic cholecystectomy (keyhole gallbladder removal) remains the standard treatment in the UK.
The C-GALL trial — the best UK evidence to date — confirms that for uncomplicated symptomatic gallstones, surgery produces better condition-specific quality of life outcomes than watchful waiting over two years, even if the difference in overall pain scores is modest. Around half of people who choose watchful waiting will end up having surgery anyway. Understanding this helps people weigh up whether to proceed with surgery or wait.
The serious complications — acute cholecystitis, bile duct obstruction, gallstone pancreatitis, and cholangitis — are clinically time-sensitive and require prompt hospital assessment. If you or someone you know develops upper right abdominal pain with fever and jaundice, that combination is a recognised red flag. Everything else — the risk factors, the follow-up, the surgical decision — is a conversation for you to have with your GP or healthcare professional.
Most gallstones stay silent for life. Those that do speak up now have a well-evidenced treatment pathway — and knowing what to look for is the first step.