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Syndrome of Inappropriate Antidiuretic Hormone (SIADH) 

Syndrome of inappropriate antidiuretic hormone occurs when the pituitary gland produces too much antidiuretic hormone. Antidiuretic hormone is what the body uses to help the kidneys control the amount of water lost through urine. Syndrome of inappropriate antidiuretic hormone (SIADH) occurs when the pituitary gland releases too much of this hormone, which leads to renal water retention in the body and can lower sodium levels in the blood (hyponatremia), which is diluted by the retained water. 

Causes of SIADH 

Syndrome of inappropriate antidiuretic hormone is typically developed as an effect of a previously existing health condition, but it can also be caused by external factors or be idiopathic. This condition typically affects older adults, though it has also been identified in children. 

Causes of SIADH include: 

  • Brain injuries, infections, diseases or abscesses 
  • Lung diseases 
  • Cancer 
  • Surgery 
  • Mental disorders 
  • Certain medications 

Symptoms of SIADH 

The severity of symptoms in patients with syndrome of inappropriate antidiuretic hormone depends on their blood sodium level. These can include: 

  • Headaches 
  • Nausea 
  • Memory problems and confusion 
  • Mood changes 
  • Muscle cramps and weakness 
  • Balance issues 
  • Seizures 
  • Coma 

Diagnosing SIADH 

Syndrome of inappropriate antidiuretic hormone isn’t easy to identify quickly, as hyponatremia is not always caused by retained water diluting a patient’s blood. Tests used to diagnose SIADH include: 

  • Urine osmolality and sodium tests 
  • Renal function tests 
  • Osmolality blood tests 
  • Comprehensive metabolic panels 
  • Toxicology screens (if medicine is the suspected cause)

Treating SIADH 

With so many potential causes of syndrome of inappropriate antidiuretic hormone, treatment plans must be created on a case-by-case basis. But one method of treatment that all patients with SIADH will undergo is a limit on their daily fluid intake to prevent more fluid from building up in the body. Medication and surgery are other treatment options that may be used depending on the primary cause of a patient’s SIADH.  

At Tampa General Hospital, we use cutting-edge technology to achieve world-class results when treating patients with SIADH and other endocrine disorders.