Understanding Calculi: Types, Causes, and Treatment

What Are Calculi?

Calculi (singular: calculus) are hardened mineral/organic deposits that form in hollow organs or ducts. Composition, location, and clinical impact vary.

Major Types

1. Urinary Calculi (Kidney/Urinary Stones)

• Locations: Kidneys, ureters, bladder, urethra.
• Composition: Calcium oxalate (80%), calcium phosphate, uric acid, struvite (infection-related), cystine.
• Symptoms: Flank/colicky pain, hematuria, nausea, urinary urgency.

2. Biliary Calculi (Gallstones)

• Locations: Gallbladder, common bile duct.
• Composition: Cholesterol (80%), pigment (bilirubin), mixed.
• Symptoms: RUQ pain post-prandial, nausea; choledocholithiasis → jaundice, cholangitis.

3. Pancreatic Calculi

• Rare; associated with chronic pancreatitis. Calcium carbonate/phosphate/protein plugs obstruct ducts → pain, malabsorption.

4. Salivary Calculi (Sialoliths)

• Submandibular (80%) > parotid ducts. Calcium phosphate/carbonate. Swelling, pain with meals.

5. Tonsillar Calculi (Tonsilloliths)

• Biofilm of bacteria, food debris, desquamated cells in tonsillar crypts. Halitosis, foreign-body sensation.

Risk Factors

• Dehydration, diet (high oxalate/sodium/animal protein), obesity, metabolic syndrome, family history, certain meds (topiramate, loop diuretics), anatomic stasis.

Treatment Principles

• Conservative: hydration, analgesics, medical expulsive therapy (alpha-blockers for ureteral stones).
• Minimally invasive: ESWL, ureteroscopy, laser lithotripsy, ERCP for bile duct stones.
• Surgical: percutaneous nephrolithotomy, cholecystectomy, sialendoscopy.
• Prevention: tailored to stone type (diet, thiazides, allopurinol, citrate, antibiotics for struvite).