CALCULUS (MEDICINE)

A 'calculus' is a stone (a concretion of material, usually mineral salts) that forms in an organ or duct of the body. Stones cause a number of important medical conditions.

Contents

Common stone diseases

Aetiology

Pathophysiology & Symptoms

Diagnosis

Treatment

See also

Common stone diseases

A number of important medical conditions are caused by stones:

★ Nephrolithiasis (kidney stones)

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★ Can cause hydronephrosis (swollen kidneys) and renal failure

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★ Can predispose to pyelonephritis (kidney infections)

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★ Can progress to bladder stones and bladder outlet obstruction

★ Cholelithiasis (gallstones)

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★ Can predispose to cholecystitis (gall bladder infections) and ascending cholangitis (biliary tree infection)

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★ Can progress to choledocholithiasis (gallstones in the bile duct) and gallstone pancreatitis (inflammation of the pancreas)

★ Rhinolith (nasal calculus)
Stones can also be asymptomatic.
Some common principles (below) apply to stones at any location, but for specifics see the particular stone type in question.

Aetiology

★ From an underlying abnormal excess of the mineral, eg. with elevated levels of calcium (hypercalcaemia) that may cause kidney stones, dietary factors for gallstones.

★ Local conditions at the site in question that promote their formation, e.g. local bacteria action (in kidney stones) or slower fluid flow rates, a possible explanation of the majority of salivary duct calculus occurring in the submandibular salivary gland.

★ Bezoars are a type of calculus found in the intestines of mostly ruminant animals and may be composed of inorganic or organic constituents.

Pathophysiology & Symptoms

Stones can cause disease by several mechanisms:

★ Irritation of nearby tissues, causing pain, swelling, and inflammation.

★ Obstruction of an opening or duct, interfering with normal flow and disrupting the function of the organ in question.

★ Predisposition to infection (often due to disruption of normal flow).

Diagnosis

Diagnostic workup varies by the stone type, but in general:

★ Clinical history and physical examination can be sufficient in some cases.

★ Imaging studies are often needed.

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★ Some stone types (mainly those with substantial calcium content) can be detected on X-ray and CT scan.

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★ Many stone types can be detected by ultrasound.

★ Factors contributing to stone formation (as in #Aetiology) are often tested:

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★ Laboratory testing can give levels of relevant substances in blood or urine.

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★ Some stones can be directly recovered (at surgery, or when they leave the body spontaneously) and sent to a laboratory for analysis of content.

Treatment

Again, treatment varies by stone type, but in general:

★ Modification of predisposing factors can sometimes slow or reverse stone formation.

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★ Medications can sometimes be used.

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★ Surgery is sometimes needed.

★ Infections due to stones have to be treated with antibiotics and/or surgery.

★ Pain is managed with medication.

See also

★ Rhinolith (nasal calculus)

★ Salivary duct calculus