Cholesterol Gallstones: Causes, Symptoms & Treatment

Cholesterol Gallstones: Causes, Risk Factors, and Treatment

Cholesterol gallstones are the most common type of gallstone in India and worldwide, accounting for approximately 80% of all gallstones. Understanding what causes cholesterol gallstones, who is at risk, and how they are treated helps patients make informed decisions about their health.

What Are Cholesterol Gallstones?

Cholesterol gallstones form when bile — the digestive fluid stored in the gallbladder — contains too much cholesterol relative to the bile salts and lecithin that normally keep cholesterol dissolved. When bile becomes supersaturated with cholesterol, it crystallises and gradually forms stones.

Composition: Cholesterol gallstones are composed of >50% cholesterol monohydrate. They may also contain calcium salts, bilirubin, and other organic material.

Appearance: Typically yellow-green to pale yellow, round or oval, with a smooth or slightly irregular surface. They range in size from a few millimetres to several centimetres.

Number: May be single (solitary) or multiple. Multiple small stones are more likely to migrate into the bile duct.

The Three-Step Process of Cholesterol Gallstone Formation

Step 1: Bile Supersaturation

The liver secretes too much cholesterol into bile relative to bile salts and phospholipids. This creates bile that is supersaturated with cholesterol — the necessary precondition for stone formation.

Causes of bile supersaturation:

• Obesity (increased hepatic cholesterol secretion)
• Oestrogen (stimulates cholesterol secretion)
• Rapid weight loss (mobilises cholesterol into bile)
• Certain medications (fibrates, oestrogen-containing contraceptives)

Step 2: Nucleation

Cholesterol crystals begin to form in supersaturated bile. This process is accelerated by:

• Mucin glycoproteins (pro-nucleating factors secreted by the gallbladder)
• Calcium salts
• Bilirubin

Step 3: Gallbladder Stasis

The gallbladder does not empty completely, allowing crystals to accumulate and grow into stones. Causes of gallbladder stasis:

• Progesterone (impairs gallbladder motility)
• Prolonged fasting
• Total parenteral nutrition (TPN)
• Spinal cord injury
• Vagotomy

Risk Factors for Cholesterol Gallstones

The "5 Fs" (Classic Teaching)

• Fat (obesity)
• Female (women are 2–3 times more likely)
• Forty (risk increases after age 40)
• Fertile (multiple pregnancies increase risk)
• Fair (Caucasian and Hispanic populations have higher risk)

Additional Risk Factors

• Family history: First-degree relatives of gallstone patients have 2–4 times higher risk
• Rapid weight loss: Losing >1.5 kg/week dramatically increases risk
• Diabetes and insulin resistance: Impairs gallbladder motility
• Metabolic syndrome: Combination of obesity, hypertension, dyslipidaemia, and insulin resistance
• Medications: Oestrogen-containing contraceptives, HRT, fibrates, octreotide, ceftriaxone
• Ileal disease or resection: Reduces bile salt reabsorption, depleting bile salt pool
• Prolonged fasting or TPN: Causes gallbladder stasis

Symptoms of Cholesterol Gallstones

Cholesterol gallstones may be:

• Silent (asymptomatic): 60–80% of cases. No treatment required.
• Symptomatic (biliary colic): Episodic severe right upper quadrant pain after fatty meals, lasting 1–6 hours.
• Complicated: Acute cholecystitis, CBD stones, pancreatitis, cholangitis.

Diagnosis

Ultrasound abdomen: First-line investigation. Sensitivity >95% for gallbladder stones. Cholesterol stones appear as echogenic foci with posterior acoustic shadowing.

Blood tests: LFTs, FBC, amylase/lipase to assess for complications.

MRCP: If CBD stones are suspected (dilated CBD, jaundice, elevated LFTs).

Treatment

Asymptomatic Cholesterol Gallstones

Watchful waiting is appropriate for most patients. Surgery is considered for:

• Very large stones (>3 cm) — risk of gallbladder cancer
• Porcelain gallbladder
• Patients undergoing bariatric surgery
• Patients with haemolytic anaemia

Symptomatic Cholesterol Gallstones

Laparoscopic cholecystectomy is the definitive treatment. It is safe, effective, and has a 1–2 week recovery.

Ursodeoxycholic acid (UDCA): Can dissolve small (<10 mm) cholesterol stones over 12–24 months. High recurrence rate after stopping. Suitable only for patients who refuse surgery or are high surgical risk.

Complicated Cholesterol Gallstones

• Acute cholecystitis: Early laparoscopic cholecystectomy within 72 hours
• CBD stones: ERCP to remove bile duct stones, followed by cholecystectomy
• Pancreatitis: Hospitalisation, supportive care, cholecystectomy after recovery

Prevention of Cholesterol Gallstones

• Maintain a healthy weight (BMI 18.5–24.9)
• Avoid rapid weight loss (≤1 kg/week)
• Eat a high-fibre, low-refined-carbohydrate diet
• Exercise regularly (150 minutes/week)
• Stay well hydrated
• Eat regular meals (avoid prolonged fasting)
• Consider UDCA during rapid weight loss (bariatric surgery)

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*Medically reviewed by Dr. Adarsh M Patil, MBBS, MS (General Surgery), Fellowship in Advanced Laparoscopy & Bariatric Surgery (Belgium). Consultant General & Laparoscopic Surgeon, Apollo Clinic Indiranagar, Bangalore.*