A calculus (plural calculi), often called a stone, is a
concretion
A concretion is a hard, compact mass of matter formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. Concretions are often ovoid or spherical in shape, although irregular ...
of material, usually
mineral
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. ( ...
salts, that forms in an organ or duct of the body. Formation of calculi is known as lithiasis (). Stones can cause a number of medical conditions.
Some common principles (below) apply to stones at any location, but for specifics see the particular stone type in question.
Calculi are not to be confused with
gastrolith
A gastrolith, also called a stomach stone or gizzard stone, is a rock held inside a gastrointestinal tract. Gastroliths in some species are retained in the muscular gizzard and used to grind food in animals lacking suitable grinding teeth. In othe ...
s.
Types
![Human gallstones 2015 G1](https://upload.wikimedia.org/wikipedia/commons/1/17/Human_gallstones_2015_G1.jpg)
* Calculi in the
urinary system
The urinary system, also known as the urinary tract or renal system, consists of the kidneys, ureters, urinary bladder, bladder, and the urethra. The purpose of the urinary system is to eliminate waste from the body, regulate blood volume and bl ...
are called
urinary calculi
Kidney stone disease, also known as nephrolithiasis or urolithiasis, is a crystallopathy where a solid piece of material (kidney stone) develops in the urinary tract. Kidney stones typically form in the kidney and leave the body in the urine s ...
and include
kidney stone
Kidney stone disease, also known as nephrolithiasis or urolithiasis, is a crystallopathy where a solid piece of material (kidney stone) develops in the urinary tract. Kidney stones typically form in the kidney and leave the body in the urine s ...
s (also called renal calculi or nephroliths) and
bladder stone
A bladder stone is a stone found in the urinary bladder.
Signs and symptoms
Bladder stones are small mineral deposits that can form in the bladder. In most cases bladder stones develop when the urine becomes very concentrated or when one is ...
s (also called vesical calculi or cystoliths). They can have any of several compositions, including mixed. Principal compositions include
oxalate
Oxalate (IUPAC: ethanedioate) is an anion with the formula C2O42−. This dianion is colorless. It occurs naturally, including in some foods. It forms a variety of salts, for example sodium oxalate (Na2C2O4), and several esters such as dimethyl o ...
and
urate
Uric acid is a heterocyclic compound of carbon, nitrogen, oxygen, and hydrogen with the formula C5H4N4O3. It forms ions and salts known as urates and acid urates, such as ammonium acid urate. Uric acid is a product of the metabolic breakdown o ...
.
* Calculi of the
gallbladder
In vertebrates, the gallbladder, also known as the cholecyst, is a small hollow organ where bile is stored and concentrated before it is released into the small intestine. In humans, the pear-shaped gallbladder lies beneath the liver, although ...
and
bile duct
A bile duct is any of a number of long tube-like structures that carry bile, and is present in most vertebrates.
Bile is required for the digestion of food and is secreted by the liver into passages that carry bile toward the hepatic duct. It ...
s are called
gallstone
A gallstone is a calculus (medicine), stone formed within the gallbladder from precipitated bile components. The term cholelithiasis may refer to the presence of gallstones or to any disease caused by gallstones, and choledocholithiasis refers to ...
s and are primarily developed from
bile salts
Bile acids are steroid acids found predominantly in the bile of mammals and other vertebrates. Diverse bile acids are synthesized in the liver. Bile acids are conjugated with taurine or glycine residues to give anions called bile salts.
Primary b ...
and
cholesterol
Cholesterol is any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell mem ...
derivatives.
* Calculi in the nasal passages (
rhinolith
A rhinolith is a stone present in the nasal cavity. The word is derived from the roots ''rhino-'' and '' -lith'', literally meaning "nose stone". It is an uncommon medical phenomenon, not to be confused with dried nasal mucus. A rhinolith usually ...
s) are rare.
* Calculi in the
gastrointestinal tract
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organ (biology), organs of the digestive syste ...
(
enteroliths) can be enormous. Individual enteroliths weighing many pounds have been reported in horses.
* Calculi in the
stomach
The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...
are called gastric calculi (Not to be confused with
gastrolith
A gastrolith, also called a stomach stone or gizzard stone, is a rock held inside a gastrointestinal tract. Gastroliths in some species are retained in the muscular gizzard and used to grind food in animals lacking suitable grinding teeth. In othe ...
s which are exogenous in nature).
* Calculi in the
salivary gland
The salivary glands in mammals are exocrine glands that produce saliva through a system of ducts. Humans have three paired major salivary glands (parotid, submandibular, and sublingual), as well as hundreds of minor salivary glands. Salivary gla ...
s are called salivary calculi (
sialoliths).
* Calculi in the
tonsil
The tonsils are a set of lymphoid organs facing into the aerodigestive tract, which is known as Waldeyer's tonsillar ring and consists of the adenoid tonsil, two tubal tonsils, two palatine tonsils, and the lingual tonsils. These organs play ...
s are called tonsillar calculi (
tonsillolith
Tonsil stones, also known as tonsilloliths, are mineralizations of debris within the crevices of the tonsils. When not mineralized, the presence of debris is known as chronic caseous tonsillitis (CCT). Symptoms may include bad breath. Generall ...
s).
* Calculi in the
vein
Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated b ...
s are called venous calculi (
phlebolith
A phlebolith is a small local, usually rounded, calcification within a vein. These are very common in the veins of the lower part of the pelvis, and they are generally of no clinical importance. When located in the pelvis they are sometimes difficu ...
s).
* Calculi in the skin, such as in
sweat gland
Sweat glands, also known as sudoriferous or sudoriparous glands, , are small tubular structures of the skin that produce sweat. Sweat glands are a type of exocrine gland, which are glands that produce and secrete substances onto an epithelial sur ...
s, are not common but occasionally occur.
* Calculi in the navel are called
omphaloliths.
Calculi are usually asymptomatic, and large calculi may have required many years to grow to their large size.
Cause
* From an underlying abnormal excess of the mineral, e.g., with elevated levels of
calcium
Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to ...
(
hypercalcaemia
Hypercalcemia, also spelled hypercalcaemia, is a high calcium (Ca2+) level in the blood serum. The normal range is 2.1–2.6 mmol/L (8.8–10.7 mg/dL, 4.3–5.2 mEq/L), with levels greater than 2.6 mmol/L defined as hypercalcemia ...
) that may cause
kidney stone
Kidney stone disease, also known as nephrolithiasis or urolithiasis, is a crystallopathy where a solid piece of material (kidney stone) develops in the urinary tract. Kidney stones typically form in the kidney and leave the body in the urine s ...
s, dietary factors for
gallstone
A gallstone is a calculus (medicine), stone formed within the gallbladder from precipitated bile components. The term cholelithiasis may refer to the presence of gallstones or to any disease caused by gallstones, and choledocholithiasis refers to ...
s.
* 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
The submandibular ganglion (or submaxillary ganglion in older texts) is part of the human autonomic nervous system. It is one of four parasympathetic ganglia of the head and neck. (The others are the otic ganglion, pterygopalatine ganglion, and cil ...
salivary gland
The salivary glands in mammals are exocrine glands that produce saliva through a system of ducts. Humans have three paired major salivary glands (parotid, submandibular, and sublingual), as well as hundreds of minor salivary glands. Salivary gla ...
.
*
Enteroliths are a type of calculus found in the
intestine
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans ...
s of
animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...
s (mostly
ruminant
Ruminants (suborder Ruminantia) are ungulate, hoofed herbivorous grazing or browsing mammals that are able to acquire nutrients from plant-based food by Enteric fermentation, fermenting it in a specialized stomach prior to digestion, principally ...
s) and
human
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
s, and may be composed of
inorganic
In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemist ...
or
organic constituents.
*
Bezoar
A bezoar is a mass often found trapped in the gastrointestinal system, though it can occur in other locations. A pseudobezoar is an indigestible object introduced intentionally into the digestive system.
There are several varieties of bezoar, s ...
s are lumps of indigestible material in the
stomach
The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...
and/or intestines; most commonly, they consist of hair (in which case they are also known as
hairball
A hairball is a small collection of hair or fur formed in the stomach of animals, and uncommonly in humans, that is occasionally vomited up when it becomes too big. Hairballs are primarily a tight elongated cylinder of packed fur, but may includ ...
s). A bezoar may form the nidus of an enterolith.
In
kidney stones
Kidney stone disease, also known as nephrolithiasis or urolithiasis, is a crystallopathy where a solid piece of material (kidney stone) develops in the urinary tract. Kidney stones typically form in the kidney and leave the body in the urine s ...
,
calcium oxalate
Calcium oxalate (in archaic terminology, oxalate of lime) is a calcium salt of oxalic acid with the chemical formula . It forms hydrates , where ''n'' varies from 1 to 3. Anhydrous and all hydrated forms are colorless or white. The monohydrate ...
is the most common mineral type (see
Nephrolithiasis
Kidney stone disease, also known as nephrolithiasis or urolithiasis, is a crystallopathy where a solid piece of material (kidney stone) develops in the urinary tract. Kidney stones typically form in the kidney and leave the body in the urine s ...
).
Uric acid
Uric acid is a heterocyclic compound of carbon, nitrogen, oxygen, and hydrogen with the formula C5H4N4O3. It forms ions and salts known as urates and acid urates, such as ammonium acid urate. Uric acid is a product of the metabolic breakdown of ...
is the second most common mineral type, but an ''
in vitro
''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology an ...
'' study showed uric acid stones and crystals can promote the formation of calcium oxalate stones.
Pathophysiology
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)
A number of important medical conditions are caused by stones:
*
Nephrolithiasis
Kidney stone disease, also known as nephrolithiasis or urolithiasis, is a crystallopathy where a solid piece of material (kidney stone) develops in the urinary tract. Kidney stones typically form in the kidney and leave the body in the urine s ...
(
kidney
The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blood ...
stones)
** Can cause
hydronephrosis
Hydronephrosis describes hydrostatic dilation of the renal pelvis and calyces as a result of obstruction to urine flow downstream. Alternatively, hydroureter describes the dilation of the ureter, and hydronephroureter describes the dilation of t ...
(swollen kidneys) and
kidney failure
Kidney failure, also known as end-stage kidney disease, is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney failure is classified as eit ...
** Can predispose to
pyelonephritis
Pyelonephritis is inflammation of the kidney, typically due to a bacterial infection. Symptoms most often include fever and flank tenderness. Other symptoms may include nausea, burning with urination, and frequent urination. Complications may ...
(kidney infections)
** Can progress to
urolithiasis
Kidney stone disease, also known as nephrolithiasis or urolithiasis, is a crystallopathy where a solid piece of material (kidney stone) develops in the urinary tract. Kidney stones typically form in the kidney and leave the body in the urine s ...
*
Urolithiasis
Kidney stone disease, also known as nephrolithiasis or urolithiasis, is a crystallopathy where a solid piece of material (kidney stone) develops in the urinary tract. Kidney stones typically form in the kidney and leave the body in the urine s ...
(
urinary bladder
The urinary bladder, or simply bladder, is a hollow organ in humans and other vertebrates that stores urine from the kidneys before disposal by urination. In humans the bladder is a distensible organ that sits on the pelvic floor. Urine enters ...
stones)
** Can progress to
bladder outlet obstruction
Bladder outlet obstruction (or obstructive uropathy) occurs when urine is unable to flow from the kidneys through the ureters and out of the bladder through the urethra. Decreased flow of urine leads to swelling of the urinary tract, called hydron ...
*
Cholelithiasis
A gallstone is a stone formed within the gallbladder from precipitated bile components. The term cholelithiasis may refer to the presence of gallstones or to any disease caused by gallstones, and choledocholithiasis refers to the presence of migr ...
(gallstones)
** Can predispose to
cholecystitis
Cholecystitis is inflammation of the gallbladder. Symptoms include right upper abdominal pain, pain in the right shoulder, nausea, vomiting, and occasionally fever. Often gallbladder attacks (biliary colic) precede acute cholecystitis. The pain l ...
(
gall bladder
In vertebrates, the gallbladder, also known as the cholecyst, is a small hollow organ where bile is stored and concentrated before it is released into the small intestine. In humans, the pear-shaped gallbladder lies beneath the liver, although ...
infections) and
ascending cholangitis
Ascending cholangitis, also known as acute cholangitis or simply cholangitis, is inflammation of the bile duct, usually caused by bacteria ascending from its junction with the duodenum (first part of the small intestine). It tends to occur if th ...
(
biliary tree
The biliary tract, (biliary tree or biliary system) refers to the liver, gallbladder and bile ducts, and how they work together to make, store and secrete bile. Bile consists of water, electrolytes, bile acids, cholesterol, phospholipids and co ...
infection)
** Can progress to
choledocholithiasis
Common bile duct stone, also known as choledocholithiasis, is the presence of gallstones in the common bile duct (CBD) (thus '' choledocho-'' + ''lithiasis''). This condition can cause jaundice and liver cell damage. Treatments include choledocholi ...
(gallstones in the bile duct) and
gallstone pancreatitis
Pancreatitis is a condition characterized by inflammation of the pancreas. The pancreas is a large organ behind the stomach that produces digestive enzymes and a number of hormones. There are two main types: acute pancreatitis, and chronic pancre ...
(inflammation of the
pancreas
The pancreas is an organ of the digestive system and endocrine system of vertebrates. In humans, it is located in the abdomen behind the stomach and functions as a gland. The pancreas is a mixed or heterocrine gland, i.e. it has both an end ...
)
* Gastric calculi can cause colic, obstruction, torsion, and necrosis.
Diagnosis
Diagnostic workup
Medical diagnosis (abbreviated Dx, Dx, or Ds) is the process of determining which disease or condition explains a person's symptoms and signs. It is most often referred to as diagnosis with the medical context being implicit. The information re ...
varies by the stone type, but in general:
* Clinical history and physical examination
* Imaging studies
** Some stone types (mainly those with substantial calcium content) can be detected on
X-ray
An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...
and
CT scan
** Many stone types can be detected by
ultrasound
Ultrasound is sound waves with frequency, frequencies higher than the upper audible limit of human hearing range, hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hea ...
* Factors contributing to stone formation (as in
#Etiology) are often tested:
**
Laboratory
A laboratory (; ; colloquially lab) is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurement may be performed. Laboratory services are provided in a variety of settings: physicia ...
testing can give levels of relevant substances in blood or urine
** 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
Modification of predisposing factors can sometimes slow or reverse stone formation. Treatment varies by stone type, but, in general:
* Healthy diet & exercise (promotes flow of energy & nutrition)
* Drinking fluids (water &
electrolytes
An electrolyte is a medium containing ions that is electrically conducting through the movement of those ions, but not conducting electrons. This includes most soluble salts, acids, and bases dissolved in a polar solvent, such as water. Upon di ...
like lemon juice, diluted vinegar eg. in pickles, salad dressings, sauces, soups,
shrubs
A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...
cocktail)
* Surgery (
lithotomy
Lithotomy from Greek for "lithos" (stone) and "tomos" ( cut), is a surgical method for removal of calculi, stones formed inside certain organs, such as the urinary tract (kidney stones), bladder ( bladder stones), and gallbladder (gallstones), ...
)
* Medication / Antibiotics
*
Extracorporeal shock wave lithotripsy
Extracorporeal shockwave therapy (ESWT) is a non-invasive, out-patient alternative to surgery for those with many joint and tendon disorders. ESWT sends acoustic shock waves into bone or soft tissue, in effect reinjuring the area on a cellular l ...
(ESWL) for removal of calculi
History
The earliest operation for curing stones is given in the ''
Sushruta Samhita
The ''Sushruta Samhita'' (सुश्रुतसंहिता, IAST: ''Suśrutasaṃhitā'', literally "Suśruta's Compendium") is an ancient Sanskrit text on medicine and surgery, and one of the most important such treatises on this subj ...
'' (6th century BCE).
[ The operation involved exposure and going up through the floor of the bladder.][Lock, Stephen etc. (2001). ''The Oxford Illustrated Companion to Medicine''. USA: Oxford University Press. 836. .]
The care of this disease was forbidden to the physicians
A physician (American English), medical practitioner (Commonwealth English), medical doctor, or simply doctor, is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through th ...
that had taken the Hippocratic Oath
The Hippocratic Oath is an oath of ethics historically taken by physicians. It is one of the most widely known of Greek medical texts. In its original form, it requires a new physician to swear, by a number of healing gods, to uphold specific e ...
because:
* There was a high probability of intraoperative and postoperative surgical complication like infection or bleeding
* The physicians would not perform surgery as in ancient cultures they were two different professions
Etymology
The word comes from Latin ''calculus'' "small stone", from ''calx'' "limestone, lime", probably related to Greek ''chalix'' "small stone, pebble, rubble",[.] which many trace to a Proto-Indo-European root for "split, break up".[ ] ''Calculus'' was a term used for various kinds of stones. In the 18th century it came to be used for accidental or incidental mineral buildups in human and animal bodies, like kidney stones and minerals on teeth.
See also
* Bezoar
A bezoar is a mass often found trapped in the gastrointestinal system, though it can occur in other locations. A pseudobezoar is an indigestible object introduced intentionally into the digestive system.
There are several varieties of bezoar, s ...
* Calculus (dental)
In dentistry, calculus or tartar is a form of hardened dental plaque. It is caused by precipitation of minerals from saliva and gingival crevicular fluid (GCF) in plaque on the teeth. This process of precipitation kills the bacterial cells w ...
* Lithotomy
Lithotomy from Greek for "lithos" (stone) and "tomos" ( cut), is a surgical method for removal of calculi, stones formed inside certain organs, such as the urinary tract (kidney stones), bladder ( bladder stones), and gallbladder (gallstones), ...
References
External links
"The Little Treatise on the Medical Treatment of the Back and of Hemorrhoids"
is a manuscript, from the 18th-century, in Arabic, which discusses the treatment of calculi
{{Authority control
Symptoms and signs
Medical terminology