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Latest revision as of 00:22, 30 July 2020

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Vindhya BellamKonda, M.B.B.S [2]

Overview

The syndrome of inappropriate antidiuretic hormone (SIADH) is a condition commonly found in individuals hospitalized for central nervous system (CNS) injury. SIADH is a syndrome characterized by excessive release of antidiuretic hormone (ADH or vasopressin) from the posterior pituitary gland or any other source, resulting in hyponatremia, and sometimes fluid overload. Syndrome of inappropriate antidiuretic hormone production (SIADH) leads to excessive water retention and thus a decrease in sodium concentration. SIADH may be occur as a result of central nervous system diseases, cancers, pulmonary diseases, and some drugs. Signs and symptoms of SIADH vary widely. Some patients with SIADH may become severely ill while others may have no symptoms at all. Common symptoms include nausea, vomiting, loss of appetite, fatigue, weakness, and altered consciousness. Blood tests of hyponatremia (sodium <135 mEq/L) and low serum osmolality (< 280 mOsm/kg) may prompt the diagnosis of SIADH. Treatment of SIADH depends on the cause. Restriction of water intake and supplementation of sodium may lead to improvement. Prognosis of SIADH varies depending on the cause.

Historical Perspective

In 1951, Leaf and Mambi first described SIADH. Later it was described by Dr Frederic Bartter in two patients with lung cancer from Boston (MA) and Bethesda (MD), in 1957.

Classification

SIADH may be classified into several sub-types based on the pattern of arginine vasopressin (AVP) secretion in response to a range of plasma osmolalities into type A, type B, type C, and type D.

Pathophysiology

Syndrome of inappropriate antidiuretic hormone production is a condition in which the body develops an excess of water and a decrease in the concentration of electrolytes. SIADH may be caused by a central nervous system diseases, cancers, pulmonary diseases, or some drugs. ADH is normally produced by the posterior pituitary gland to prevent water loss in the kidneys. In SIADH, ADH level rises above the normal level. Aquaporins are localized on storage vesicles in the cytoplasm of the epithelial cells which make up the collecting ducts of the kidneys. High ADH level stimulates mass fusion of aquaporin-carrying storage vesicles with the plasma membrane. High aquaporin density facilitates high diffusion of water across the plasma membrane. Excess water is reabsorbed from the nephrons and is returned to the blood. A mutation affecting the gene for the renal V2 receptor might cause SIADH.

Causes

Syndrome of inappropriate antidiuretic hormone is caused by excess of renal water reabsorption through inappropriate antidiuretic hormone secretion. There are various causes attributed to SIADH ranging from malignancies, medications, central nervous system causes, and infectious. Some of the most common causes of SIADH include malignancies, like small cell lung cancer and medications, such as selective serotonin reuptake inhibitors and carbamazepine.

Differential diagnosis

Syndrome of inappropriate antidiuretic hormone (SIADH) must be differentiated from other causes of hyponatremia, such as cerebral salt wasting syndrome, adrenal insufficiency, hypopituitarism, and psychogenic polydipsia.

Epidemiology and Demographics

Syndrome of inappropriate antidiuretic hormone (SIADH) can occur at any age. Its incidence depends upon various possible etiologies. Prevalence of SIADH was estimated to be 2500-3000 cases per 100,000 individuals. The incidence and prevalence of SIADH in particular is less thoroughly studied in the literature. Hospitalized patients with plasma sodium concentration <125 mmol/l show an overall mortality of 28000 per 100,000 patients. The incidence of SIADH increases with age. The prevalence and incidence of SIADH does not vary by gender. There is no racial predilection to SIADH.

Risk Factors

The most common risk factors of Syndrome of inappropriate antidiuretic hormone (SIADH) are malignancy, pulmonary disorders, CNS disorders, and medications.

Screening

There is insufficient evidence to recommend routine screening for SIADH.

Natural History, Complications, and Prognosis

The symptoms of SIADH can occur at any age. If left untreated, it can lead to complications, such as confusion, seizures, stupor, and coma. Some of the complications of SIADH treatment are include cerebral edema and central pontine myelinolysis, which are seen with rapid sodium correction. The prognosis of SIADH depends primarily on its cause. If the cause is medications, SIADH usually improves after discontinuing the medications. SIADH secondary to an infection, improves with the treatment of the infection. SIADH secondary to cancers, has poor outcome. Patients with SIADH have different signs, symptoms and prognosis depending on the etiology of SIADH. Serum sodium concentration at short-term follow-up is predictive of long-term survival.

Diagnosis

History and Symptoms

Symptoms of SIADH depend on the level of sodium in the blood and the rate at which the level of sodium falls. Symptoms may be non-specific, such as generalized fatigue and weakness; but in case of severe disease, symptoms, such as irritability, nausea, vomiting, muscle weakness and cramps, loss of appetite, confusion, personality changes, hallucinations, seizures, stupor, and coma may be seen.

Physical Examination

Physical examination of patients with syndrome of inappropriate antidiuretic hormone (SIADH) is usually remarkable for ill and sometimes confused appearance, orthostatic hypotension, Cheyne-Stokes respiration, dysarthria, altered mental status, confusion, disorientation, delirium, generalized muscle weakness, generalized seizures, coma, myoclonus, tremor, asterixis, hyporeflexia, and ataxia.

Laboratory Findings

Laboratory findings which are helpful in diagnosing syndrome of inappropriate antidiuretic hormone (SIADH) include serum electrolytes (especially sodium), blood urea nitrogen (BUN), creatinine, glucose levels, and osmolality. Laboratory findings in patients with SIADH may show hyponatremia (sodium <135 mEq/L) and low serum osmolality (< 280 mOsm/kg). Patients with SIADH have elevated urinary sodium level (> 20 mMol/L) and urine osmolality (generally > 100 mOsm/L). Patients with SIADH also have low BUN, normal creatinine, hypouricemia, and hypoalbuminemia.

Electrocardiogram

Electrocardiogram (EKG) may be helpful in the diagnosis of SIADH. Findings on an EKG suggestive of SIADH are like classic Brugada like pattern, include downward coving of ST-segment and T-wave inversion in the anterior precordial leads. The EKG changes will be normalized after the sodium levels were corrected.

Xray

An x-ray may be helpful in the diagnosis of Lung cancer, which is one of the most common causes of SIADH. The findings include hilar/perihilar mass and mediastinal widening.

CT scan

Chest CT scan may be helpful in the diagnosis of lung cancer, which is one of the most common cause of SIADH. Findings on CT scan suggestive of lung cancer include numerous enlarged lymph nodes and direct infiltration of adjacent structures.

MRI

Brain MRI may be helpful in the diagnosis of SIADH. Findings on MRI suggestive of SIADH include brain abscess, subarachnoid hemorrhage, and meningitis.

Ultrasound

There are no ultrasound findings associated with SIADH.

Other Imaging Findings

There are no other imaging findings for SIADH.

Other Diagnostic Studies

There are no additional diagnostic findings for SIADH.

Treatment

Medical Therapy

Treatment of syndrome of inappropriate antidiuretic hormone (SIADH) depends on the etiology. For immediate improvement, all patients with syndrome of inappropriate antidiuretic hormone (SIADH) require strict restriction of their daily water intake and correction of serum sodium levels. The serum sodium can be corrected depending on the initial sodium levels of the patient. Mild cases can be managed easily with exclusive fluid restriction. Moderate cases of SIADH are treated with loop diuretics and normal saline; whereas, 3% hypertonic saline may be used in severe cases. In emergency settings, vasopressin-2 receptor antagonists (conivaptan or tolvaptan) are used. The definitive treatment of SIADH involves treatment of the underlying condition. Urea, demeclocycline, and lithium are also used in the treatment of SIADH.

Surgery

The definitive treatment of SIADH involves treatment of the underlying condition. SIADH resulting from a carcinoma may require surgery, radiation therapy, or chemotherapy.

Primary prevention

Effective measures for the primary prevention of SIADH include regular monitoring of drugs by the health care provider and screening for cancers.

Secondary prevention

There are no secondary preventive measures available for SIADH.

References

@@ Line 4: / Line 4: @@
 ==Overview==
-The syndrome of inappropriate antidiuretic hormone ([[SIADH]]) is a condition commonly found in individuals hospitalized for [[central nervous system]] (CNS) injury. SIADH is a syndrome characterized by excessive release of [[Vasopressin|antidiuretic hormone]] (ADH or [[vasopressin]]) from the [[posterior pituitary]] gland or any other source, resulting in [[hyponatremia]], and sometimes [[fluid]] overload. Syndrome of inappropriate antidiuretic hormone production (SIADH) leads to excessive water retention and thus a decrease in [[sodium]] concentration. SIADH may be occur as a result of [[Central nervous system disease|central nervous system diseases]], [[cancer]]s, [[pulmonary disease]]s and some [[drugs]]. Signs and symptoms of [[SIADH]] vary widely. Some patients with SIADH may become severely ill while others may have no [[symptoms]] at all. Common symptoms include [[nausea]], [[vomiting]], [[loss of appetite]], [[fatigue]], [[weakness]] and altered [[consciousness]]. Blood tests of [[hyponatremia]] ([[sodium]] <135 mEq/L) and low serum [[osmolality]] (<280 mOsm/kg) may prompt the [[diagnosis]] of SIADH. [[Treatment IND|Treatment]] of SIADH depends on the [[Causes|cause]]. Restriction of [[Water|wate]]<nowiki/>r intake and supplementation of [[sodium]] may lead to improvement. [[Prognosis]] of SIADH varies depending on the [[Causes|cause]].
+The syndrome of inappropriate antidiuretic hormone ([[SIADH]]) is a condition commonly found in individuals hospitalized for [[Central nervous system|central nervous system (CNS)]] injury. SIADH is a syndrome characterized by excessive release of [[Vasopressin|antidiuretic hormone]] ([[Antidiuretic hormone|ADH]] or [[vasopressin]]) from the [[Posterior pituitary|posterior pituitary gland]] or any other source, resulting in [[hyponatremia]], and sometimes [[fluid]] overload. Syndrome of inappropriate antidiuretic hormone production (SIADH) leads to excessive [[water retention]] and thus a decrease in [[sodium]] concentration. [[Syndrome of inappropriate antidiuretic hormone|SIADH]] may be occur as a result of [[Central nervous system disease|central nervous system diseases]], [[cancer]]s, [[pulmonary disease]]s, and some [[drugs]]. Signs and symptoms of [[Syndrome of inappropriate antidiuretic hormone|SIADH]] vary widely. Some patients with [[Syndrome of inappropriate antidiuretic hormone|SIADH]] may become severely ill while others may have no [[symptoms]] at all. Common symptoms include [[nausea]], [[vomiting]], [[loss of appetite]], [[fatigue]], [[weakness]], and altered [[consciousness]]. Blood tests of [[hyponatremia]] ([[sodium]] <135 mEq/L) and low serum [[osmolality]] (< 280 mOsm/kg) may prompt the [[diagnosis]] of [[Syndrome of inappropriate antidiuretic hormone|SIADH]]. [[Treatment IND|Treatment]] of [[Syndrome of inappropriate antidiuretic hormone|SIADH]] depends on the [[Causes|cause]]. Restriction of [[Water|wate]]<nowiki/>r intake and supplementation of [[sodium]] may lead to improvement. [[Prognosis]] of [[Syndrome of inappropriate antidiuretic hormone|SIADH]] varies depending on the [[Causes|cause]].
 ==Historical Perspective==
-Syndrome of inappropriate antidiuretic hormone secretion was initially described by Leaf and Mambi in the year 1951. Later it was described by researchers from Boston, Massachusetts and Bethesda, Maryland (including Dr Frederic Bartter) in two patients with [[Lung cancer|lung cance]]<nowiki/>r in the year 1957. [[SIADH]] is occasionally referred to as [[Schwartz-Bartter syndrome]].
+In 1951, Leaf and Mambi first described [[Syndrome of inappropriate antidiuretic hormone|SIADH]]. Later it was described by Dr Frederic Bartter in two patients with [[lung cancer]] from Boston (MA) and Bethesda (MD), in 1957.
 ==Classification==
-Four different types of [[SIADH]], were[[ classified]] defined by the pattern of[[ AVP]] secretion across a range of [[Plasma osmolality|plasma osmolalities]]. Type A, Type B, Type C, Type D.
+[[SIADH]] may be classified into several sub-types based on the pattern of [[arginine vasopressin|arginine vasopressin (AVP)]] secretion in response to a range of [[plasma osmolality|plasma osmolalities]] into type A, type B, type C, and type D.
 ==Pathophysiology==
+[[SIADH|Syndrome of inappropriate antidiuretic hormone production]] is a condition in which the body develops an excess of [[water]] and a decrease in the concentration of [[electrolytes]]. [[SIADH]] may be caused by a [[central nervous system]] [[diseases]], [[cancers]], pulmonary diseases, or some [[drugs]]. [[ADH]] is normally produced by the posterior [[pituitary]] gland to prevent water loss in the [[kidneys]]. In [[SIADH]], [[ADH]] level rises above the normal level. [[Aquaporins]] are localized on storage [[vesicles]] in the [[cytoplasm]] of the [[epithelial cells]] which make up the [[collecting ducts]] of the [[kidneys]]. High [[ADH]] level stimulates mass fusion of [[aquaporin]]-carrying storage vesicles with the [[plasma membrane]]. High [[aquaporin]] density facilitates high diffusion of water across the [[plasma]] membrane. Excess [[water]] is reabsorbed from the [[nephrons]] and is returned to the [[blood]]. A [[mutation]] affecting the [[gene]] for the [[renal]] [[V2 receptor]] might cause SIADH.
-Clinical picture of [[SIADH]] may result from[[ genetic]] disorders that result in [[Diuresis|antidiuresis]]. A[[ mutation]] affecting the gene for the[[ renal]] V2 receptor, which some investigators have named nephrogenic syndrome of inappropriate antidiuresis, has been found to cause[[ clinically]] significant[[ hyponatremia]]. [[Congenital]] [[nephrogenic diabetes insipidus]] is characterized by a resistance of the renal [[collecting duct]] to the action of the arginine vasopressin [[hormone]] responsible for the inability of the[[ kidney]] to [[concentrate]][[ urine]]. The X-linked form is due to inactivating mutations of the vasopressin 2 receptor gene leading to a loss of function of the mutated receptors. Conversely, the nephrogenic syndrome of inappropriate antidiuresis (NSIAD) is linked to a constitutive activation of the V(2)-receptor due to activating[[ mutations]] with clinical and [[biological]] features of inappropriate antidiuresis but with low or undetectable plasma [[arginine vasopressin]] hormone levels.
 ==Causes==
-SIADH is caused by excess of [[renal]] water reabsorption through inappropriate [[antidiuretic hormone]] secretion, there are various causes attributed to [[SIADH]] ranging from [[malignancies]],  [[drugs]], [[central nervous system]] causes, [[infectious]]. Some of the most common causes of SIADH include malignancies, like [[small cell lung cancer]] and [[medications]] like [[Selective serotonin reuptake inhibitor|selective serotonin reuptake inhibitors]] and [[Carbamazepine|carbamazepine.]]
+[[SIADH|Syndrome of inappropriate antidiuretic hormone]] is caused by excess of [[renal]] water reabsorption through inappropriate [[antidiuretic hormone]] secretion. There are various causes attributed to [[SIADH]] ranging from [[malignancies]], [[medications]], [[central nervous system]] causes, and [[infectious]]. Some of the most common causes of [[SIADH]] include malignancies, like [[small cell lung cancer]] and [[medications]], such as [[Selective serotonin reuptake inhibitor|selective serotonin reuptake inhibitors]] and [[Carbamazepine|carbamazepine]].
 ==Differential diagnosis==
+Syndrome of inappropriate antidiuretic hormone (SIADH) must be differentiated from other causes of [[hyponatremia]], such as [[cerebral salt wasting syndrome]], [[adrenal insufficiency]], [[hypopituitarism]], and [[psychogenic polydipsia]].
-[[SIADH]] consists of[[ hyponatremia]], inappropriately elevated urine[[ osmolality]], excessive urine [[sodium]] and decreased serum[[ osmolality]] in a [[euvolemic]] patient without [[edema]]. These findings should occur in the absence of [[diuretic]] treatment with normal[[ cardiac]], [[renal]], [[adrenal]], [[hepatic]] and [[Thyroid|thyroid function]].[[ Hyponatremia]] occurs in about 30% of hospitalized patients and SIADH is the most frequent cause of [[hyponatremia]]. Differentiating hyponatremia due to SIADH from other causes of [[hyponatremia]] becomes essential to evaluate the [[Treatment IND|treatment]] plan.
 ==Epidemiology and Demographics==
-[[SIADH]] can occur at any age. The incidence of SIADH depends on various possible etiologies. [[Hyponatremia]] is the most common electrolyte abnormality in hospitalized patients.
+Syndrome of inappropriate antidiuretic hormone (SIADH) can occur at any age. Its [[incidence]] depends upon various possible [[etiologies]]. [[Prevalence]] of [[SIADH]] was estimated to be 2500-3000 cases per 100,000 individuals. The [[incidence]] and [[prevalence]] of [[SIADH]] in particular is less thoroughly studied in the literature. Hospitalized patients with plasma [[sodium]] concentration <125 mmol/l show an overall mortality of 28000 per 100,000 patients. The [[incidence]] of [[SIADH]] increases with [[age]]. The [[prevalence]] and [[incidence]] of [[SIADH]] does not vary by gender. There is no racial predilection to [[SIADH]].
-Prevalence of[[ hyponatremia]] in hospitalized patients from multiple studies came to be about 2500 to 30000 per 100, 000 persons. [[SIADH]] is the most common clinical setting in hospitalized patients with [[hyponatremia]]. The [[incidence]] and[[ prevalence]] of SIADH in particular is less thoroughly studied in the literature.
 ==Risk Factors==
-The most common risk factors of [[SIADH]] are[[ malignancy]], [[pulmonary disorders]], [[CNS]] disorders and[[ medications]].
+The most common risk factors of Syndrome of inappropriate antidiuretic hormone (SIADH) are [[malignancy]], [[pulmonary]] disorders, [[CNS]] disorders, and [[medications]].
 ==Screening==
-There is insufficient evidence to recommend routine screening for SIADH.
+There is insufficient [[evidence]] to recommend routine [[Screening (medicine)|screening]] for [[SIADH]].
 ==Natural History, Complications, and Prognosis==
-===Natural History===
+The [[symptoms]] of SIADH can occur at any age. If left untreated, it can lead to [[complications]], such as [[confusion]], [[seizures]], [[stupor]], and [[coma]]. Some of the [[complications]] of SIADH treatment are include [[cerebral edema]] and [[central pontine myelinolysis]], which are seen with rapid [[sodium]] correction. The prognosis of SIADH depends primarily on its cause. If the cause is [[drug|medications]], SIADH usually improves after discontinuing the [[drug|medications]]. SIADH secondary to an [[infection]], improves with the treatment of the [[infection]]. SIADH secondary to [[cancers]], has poor outcome. [[Patients]] with SIADH have different signs, symptoms and [[prognosis]] depending on the [[etiology]] of SIADH. Serum [[sodium]] concentration at short-term follow-up is predictive of long-term survival.
-The [[symptoms]] of [[SIADH]] can occur at any age. If untreated can lead to[[ complications]] such as [[confusion]], [[seizures]], [[stupor]] and [[coma]].
-===Complications===
-Some of the [[complications]] of treatment of [[SIADH]] are, [[cerebral edema]] and[[ central pontine myelinolysis]] which are seen with rapid [[sodium]] correction.
-===Prognosis===
-The prognosis of [[Syndrome of inappropriate antidiuretic hormone]] (SIADH) depends primarily on its cause. If the cause is [[drug|medication]]s, SIADH usually improves after discontinuing the medication. SIADH secondary to an [[infection]], improves with the treatment of the infection. Whereas, SIADH secondary to [[cancer]]s, has poor outcome.[[ Patients]] with SIADH have different signs, symptoms and [[prognosis]] depending on the [[etiology]] of SIADH. Serum [[sodium]] concentration at short-term follow-up is predictive of long-term survival. Rapid correction of serum [[sodium]] concentration can lead to various complications.
 ==Diagnosis==
 ===History and Symptoms===
-The main pathology in patients with [[SIADH]] is excessive[[ water]] retention and [[hyponatremia]]. [[Symptoms]] of SIADH depend on the level of [[sodium]] in the blood and the rate at which the level of [[sodium ]]falls. Symptoms may be non-specific such as generalised [[fatigue]] and weakness but if severe, symptoms such as [[irritability]], [[nausea]], [[vomiting]], [[muscle weakness]] and [[cramps]], [[loss of appetite]], [[confusion]], [[personality changes]], [[hallucinations]], [[seizures]], [[stupor]] and [[coma]] may be seen.
+[[Symptoms]] of SIADH depend on the level of [[sodium]] in the [[blood]] and the rate at which the level of [[sodium]] falls. [[Symptoms]] may be non-specific, such as generalized [[fatigue]] and [[weakness]]; but in case of severe disease, [[symptoms]], such as [[irritability]], [[nausea]], [[vomiting]], [[muscle weakness]] and [[cramps]], [[loss of appetite]], [[confusion]], [[personality changes]], [[hallucinations]], [[seizures]], [[stupor]], and [[coma]] may be seen.
 ===Physical Examination===
-The physical examination findings of [[SIADH]] depend on the level of [[sodium]] and rate of change of sodium levels. The physical examination findings in case of mild to moderate SIADH include [[Headache]], [[lethargy]], [[impaired memory]], [[Gait abnormality|gait instability]], and frequent [[fall]]s. In case of severe SIADH, findings such as [[confusion]], [[hallucinations]], [[dysarthria]], [[psychosis]], [[seizures]], [[hemiplegia]], [[weakness|limb weakness]], [[tremor|tremors]], and [[coma]] may ensue.
+Physical examination of patients with syndrome of inappropriate antidiuretic hormone (SIADH) is usually remarkable for ill and sometimes confused appearance, [[orthostatic hypotension]], [[Cheyne-Stokes respiration]], [[dysarthria]], [[altered mental status]], [[confusion]], [[disorientation]], [[delirium]], generalized [[muscle weakness]], [[generalized seizures]], [[coma]], [[myoclonus]], [[tremor]], [[asterixis]], [[hyporeflexia]], and [[ataxia]].
 ===Laboratory Findings===
-Laboratory findings which are helpful in diagnosing [[SIADH]] include, serum [[electrolytes]], especially[[ sodium]], [[BUN]], [[creatinine]], [[glucose]] levels, and [[osmolality]].  Laboratory findings in patients with[[ syndrome of inappropriate antidiuretic hormone]] may show [[hyponatremia]] ([[sodium]] <135 mEq/L) and low serum [[osmolality]] (<280 mOsm/kg). Patients with syndrome of inappropriate antidiuretic hormone show elevated urinary [[sodium]] level (>20 mmol/L) and urine [[osmolality ]] (generally >100 mOsm/L). Patients with SIADH also have low
+[[Laboratory]] findings which are helpful in diagnosing syndrome of inappropriate antidiuretic hormone (SIADH) include [[serum]] [[electrolytes]] (especially [[sodium]]), [[BUN|blood urea nitrogen (BUN)]], [[creatinine]], [[glucose]] levels, and [[osmolality]]. Laboratory findings in patients with SIADH may show [[hyponatremia]] ([[sodium]] <135 mEq/L) and low [[serum]] [[osmolality]] (< 280 mOsm/kg). Patients with SIADH have elevated [[urinary]] [[sodium]] level (> 20 mMol/L) and [[urine]] [[osmolality]] (generally > 100 mOsm/L). Patients with SIADH also have low [[BUN]], normal [[creatinine]], [[hypouricemia]], and [[hypoalbuminemia]].
-[[BUN]], normal [[creatinine]], [[hypouricemia]] and [[hypoalbuminemia]].
 ===Electrocardiogram===
+[[EKG|Electrocardiogram (EKG)]] may be helpful in the [[diagnosis]] of SIADH. Findings on an [[EKG]] suggestive of SIADH are like classic [[Brugada]] like pattern, include downward coving of [[ST-segment]] and [[T-wave inversion]] in the anterior [[precordial]] leads. The [[EKG]] changes will be normalized after the [[sodium]] levels were corrected.
-[[EKG]] may be helpful in the [[diagnosis]] of [[SIADH]] in rare circumstances. ome studies have reported classic [[Brugada]] like pattern (downward coving of ST-segment with T wave inversion is present in the anterior [[Precordial|precordia]]<nowiki/>l leads) in patients with hyponatremia ,the [[EKG]] changes normalized after the [[sodium]] levels were corrected.
 ===Xray===
-Imaging Studies, such as [[x-ray]], [[CT]] and [[MRI]] may be help find the causes of syndrome of inappropriate antidiuretic hormone.
+An [[x-ray]] may be helpful in the [[diagnosis]] of [[Lung cancer]], which is one of the most common [[causes]] of SIADH. The findings include [[hilar]]/perihilar mass and [[mediastinal widening]].
 ===CT scan===
-Imaging Studies, such as [[x-ray]], [[CT]] and [[MRI]] may be help find the causes of syndrome of inappropriate antidiuretic hormone.
+Chest [[CT scan]] may be helpful in the diagnosis of [[lung cancer]], which is one of the most common [[Causes|cause]] of SIADH. Findings on [[CT scan]] suggestive of [[lung cancer]] include numerous enlarged [[lymph nodes]] and direct infiltration of adjacent structures.
 ===MRI===
-MRI is one of the important diagnostic tool to find the CNS causes of SIADH
+[[Brain]] [[MRI]] may be helpful in the diagnosis of SIADH. Findings on [[MRI]] suggestive of SIADH include [[brain abscess]], [[subarachnoid hemorrhage]], and [[meningitis]].
 ===Ultrasound===
-There are no [[ultrasound]] findings associated with[[ SIADH]].
+There are no [[ultrasound]] findings associated with SIADH.
 ===Other Imaging Findings===
-There are no other specific  imaging findings for[[ SIADH]]
+There are no other [[imaging]] findings for SIADH.
 ===Other Diagnostic Studies===
-There are no additional [[diagnostic]] findings for [[SIADH]].
+There are no additional [[diagnostic]] findings for SIADH.
 ==Treatment==
 ===Medical Therapy===
-Treatment of [[syndrome of inappropriate antidiuretic hormone]] depends on the [[etiology]]. For immediate improvement, all patients with [[SIADH]] require strict restriction of their daily[[ water]] intake and correction of serum sodium levels. The serum sodium can can be corrected depending on the initial sodium levels of the patient. Mild cases can be managed easily with exclusive fluid restriction. Moderate cases of SIADH are treated with [[loop diuretic]]s and normal [[saline]], whereas, 3% hypertonic saline may be used in severe cases. In emergency settings, [[Vasopressin]]-2 receptor antagonists (aquaretics, such as [[conivaptan]] or[[ tolvaptan]]) are used.  The definitive treatment of SIADH involves treatment of the underlying condition. [[ urea]], [[demeclocycline]] and [[lithium]] are also used in the treatment of [[SIADH]].
+Treatment of syndrome of inappropriate antidiuretic hormone (SIADH) depends on the [[etiology]]. For immediate improvement, all patients with syndrome of inappropriate antidiuretic hormone (SIADH) require strict restriction of their daily [[water]] intake and correction of [[serum]] [[sodium]] levels. The [[serum]] [[sodium]] can be corrected depending on the initial [[sodium]] levels of the patient. Mild cases can be managed easily with exclusive [[fluid]] restriction. Moderate cases of SIADH are treated with [[loop diuretics]] and [[normal saline]]; whereas, 3% [[hypertonic]] [[Saline (medicine)|saline]] may be used in severe cases. In emergency settings, [[Arginine vasopressin receptor 2|vasopressin-2 receptor]] [[antagonists]] ([[conivaptan]] or [[tolvaptan]]) are used. The definitive treatment of SIADH involves treatment of the underlying condition. [[Urea]], [[demeclocycline]], and [[lithium]] are also used in the treatment of SIADH.
 ===Surgery===
-The definitive treatment of SIADH involves treatment of the underlying condition. SIADH resulting from a carcinoma may require [[surgery]], [[radiation therapy]], or [[chemotherapy]].
+The definitive treatment of SIADH involves [[treatment]] of the underlying condition. SIADH resulting from a [[carcinoma]] may require [[surgery]], [[radiation therapy]], or [[chemotherapy]].
 ===Primary prevention===
-Effective measures for the primary prevention of SIADH include regular monitoring of drugs by the health care provider and screening for cancers.
+Effective measures for the primary [[Prevention (medical)|prevention]] of SIADH include regular [[Monitoring competence|monitoring]] of [[drugs]] by the health care provider and [[Screening (medicine)|screening]] for [[cancers]].
 ===Secondary prevention===
-There are no secondary preventive measures available for SIADH.
+There are no secondary [[Preventive care|preventive]] measures available for SIADH.
 ==References==
 {{Reflist|2}}
+[[Category:Medicine]]
 [[Category:Endocrinology]]
+[[Category:Nephrology]]
 [[Category:Neurology]]
-[[Category:Nephrology]]
+[[Category:Up-To-Date]]
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