SIADH – Definition, Symptoms, Causes, Diagnosis and Treatment

Are muscular cramps, fatigue and headache ruining your day? Think you are having hallucinations? You may be suffering from SIADH, a rare medical condition that affects only a few in the population.

SIADH Definition

What is SIADH? Simply put, it is a health condition that is characterized by abnormally low sodium levels in the body. “SIADH” is the abbreviated form of “Syndrome of Inappropriate Antidiuretic Hormone Secretion”. It is commonly seen in people suffering from some types of cancer, heart failure or affected hypothalamus.

SIADH Causes

SIADH is actually caused due to increased levels of the ADH hormone. ADH or Antidiuretic hormone is released by the pituitary gland and helps the kidney to function properly. It helps maintain the balance of water and minerals like sodium and potassium in the urine and the bloodstream. An excess of this hormone leads to the expulsion of large amounts of sodium through urine while the water level remains almost unchanged. A healthy amount of sodium is vital for proper functioning of the body. Naturally, low sodium level can be very harmful for the body.

SIADH arises when the sodium level drops due to some reason. Some of the most common causes for a reduction in sodium level are:


Cancerous tumors, particularly small cell lung tumors, can give rise to SIADH. This happens because tumors may begin creating their own ADH (Antidiuretic Hormone) or impact the pituitary gland to boost ADH production.


Some anti-epileptic drugs, anti-depressants and certain drugs that are used to treat diabetes, depression and blood pressure may also activate ADH secretion. General anesthesia may be another ADH enhancer. Some of these medicines affect liquid output from kidneys thereby bringing on this syndrome.

Lung Disease

Lung disorders such as lung cancer and lung abscess may also give rise to increased ADH production in some cases.


Certain infections of the CNS (Central Nervous System) such as Guillain-Barre Syndrome result in swelling of the nerves and trigger a release of the ADH hormone.


Malignant conditions like Prostate cancer, Pancreatic cancer, Leukemia and Lymphoma can also lead to this condition.

Chest Disorders

In some cases, chest diseases like tuberculosis and Pneumonia can be causes of SIADH.

Brain Diseases

Brain disorders like Meningitis are another reason behind the appearance of SIADH syndrome in many patients. Head injuries and brain tumors are other possible causes.

Mental Disorders

Major mental diseases like Psychosis are often held responsible for the showing up of this disease.


This condition is characterized by an inflammation of the brain. It is caused by lead poisoning or the bite of an infected mosquito.

SIADH Symptoms

People suffering from SIADH experience a number of symptoms. Some of the most commonly observed SIADH signs and symptoms are:


The low sodium levels may give rise to headaches in affected people.


Most SIADH sufferers experience a tiredness or lethargic feeling which impairs their daily activities.


Reduced sodium level may cause the suffering person fidget and have an uncomfortable feeling.


People having SIADH may also feel nauseous. Many sufferers feel like vomiting while they are having an abnormally reduced sodium level.


The physical discomfort can also lead to mental confusion in some patients.


Physical symptoms and mental confusion also make some affected people suffer from mild hallucinations.

Seizures and Fainting

If the condition is not timely treated, the affected people may suffer from loss of consciousness and seizures.


A person may also experience muscular cramps or spasms due to low sodium levels in the body.

SIADH Risk Factors

In severe cases of SIADH, the patient may suffer from a failure of a vital organ like heart, lungs, liver or kidney. If the person is not treated immediately in emergency care, it may even result in death. In patients who have recently undergone a surgery in the nervous system SIADH may lead to Hyponatremia, a condition that is also characterized by low sodium level in bloodstream. But while Hyponatremia is seen mostly in patients with neurosurgery, SIADH occur in patients with a number of other medical conditions like head trauma, memingitis, asthma and more.

SIADH Diagnosis

Doctors normally diagnose this syndrome by taking blood and urine samples and checking them for any abnormality in sodium levels. If a tumor or infection is suspected, additional SIADH tests like kidney biopsies, imaging scans and some more blood examinations have to be carried out. If the condition is serious as in case of an organ failure, the person may need dialysis or oxygen therapy while diagnostic tests are being carried out. Intravenous fluids also need to be given to such people.

The diagnosis of SIADH often needs a urine osmolality examination. SIADH urine osmolality test is a very important diagnostic examination. The osmotic pressure of the urine is checked to find out if the person is really having SIADH.

SIADH Treatment

The treatment of SIADH usually depends on the health of the patient and the causative agent of the condition. The fluid intake of the person is normally restricted to bring a temporary relief. For curing SIADH drugs like ADH receptor agonists are also provided. These medicines slow down the production of ADH hormones thus bringing sodium levels back to normal.

The long-term treatment involves finding a cure to the cause of the condition in the affected person. If the person is having SIADH due to cancer, radiation therapes or chemotherapies may be needed. In some cases, surgery is also necessary.

Antibiotics prove to be effective SIADH medications in people suffering from infections.

Early treatment, proper medications and effective SIADH management with fluid restriction can help an affected person make a fast recovery from this syndrome.

If there is no timely treatment of SIADH complications like hyponatremia and even organ failure are very likely. So it is very important that the condition is treated as early and as properly as possible. If you notice symptoms of SIADH in children or adults in your family or even yourself, it is time you immediately seek medical attention. Early treatment can help you keep many uncomfortable situations at bay, enjoy a healthy life and be with your loved ones.


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