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Hyponatremia is a condition in which the level of sodium in the blood is too low. This occurs when there is an imbalance in the amount of water and sodium in the body—too little sodium for the amount of water present. As a result, water moves into the body’s cells causing them to swell. This condition may be serious. It requires care from your doctor.

There are different types of hyponatremia, each resulting in low sodium in the body:

Causes of hyponatremia include:

• Too much fluid intake
• Diarrhea or vomiting
• Sweating
• Conditions such as:
  • Kidney failure
  • Heart failure
  • Cirrhosis (a type of liver damage)
  • Hypothyroidism (underactive thyroid)
  • Pancreatitis (inflammation of the pancreas)
  • Peritonitis (inflammation of the abdominal lining)
  • Blockage of small intestine
  • Gland disorders (eg, Addison’s disease , syndrome of inappropriate secretion of antidiuretic hormone)
  • Cancer
• Taking certain medicines such as:
  • Diuretics (medicines that increase urine output)
  • Certain psychiatric medicines

Kidney Failure

Kidney failure is one condition that may cause hyponatremia.

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Risk factors include:

• Drinking too much fluid (eg, water)
• Taking certain medicines
• Having certain conditions
• Having certain medical procedures (eg, prostate surgery )
• Participating in endurance exercise, like running marathons
• Being of advanced age
• IV treatment—While in the hospital, fluids may be delivered through a needle in the vein. In some cases, this may lead to hyponatremia.

With mild hyponatremia, you may have no symptoms at all. During more severe cases, symptoms may include:

• Headache
• Sluggishness
• Confusion
• Hallucinations
• Nausea
• Irritability
• Loss of appetite
• Restlessness
• Muscle twitching
• Seizures
• Unresponsiveness
• Coma

If left untreated, the condition may lead to death.

Your doctor will:

• Ask about your symptoms
• Ask about your fluid intake
• Take your medical history
• Do a physical exam

Tests may include:

• Blood tests—to check the sodium level in your blood, as well as other blood tests to check the functioning of your organs (eg, kidneys, heart, liver)
• Urine test—to check the sodium level in your urine

Treatment may depend on:

• What is causing the low sodium level
• How long the sodium level has been low
• How low the sodium level is

In most cases, your doctor will want to correct the sodium level slowly. Serious complications may occur when sodium levels rise too rapidly. Treatment options include:

• Restricting the amount of fluids consumed
• Identifying the underlying cause and getting proper treatment
• Taking medicines to help remove extra fluid from your body
• Using an IV to deliver sodium and fluid to correct the balance

To help reduce your chance of getting hyponatremia, take these steps:

• If participating in sports, drink only as much water or sports drinks as you need to quench your thirst. Sports drinks that provide electrolytes, such as sodium, may be helpful during endurance events.
• Work with your doctor to effectively manage any conditions that you may have.