Low Sodium Explained

Medically Reviewed By Jenneh Rishe, RN
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Low sodium levels in the blood, or hyponatremia, is the most common electrolyte disorder. Without treatment, it can lead to many issues, such as seizures, osteoporosis, and brain swelling. This article will define low sodium. It will also discuss the symptoms, causes, and risk factors of the condition. Finally, it will go over the treatments and prevention methods for low sodium.

What is low sodium?

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Low sodium, also known as hyponatremia, is when the sodium level in your blood is low. Low sodium is the most common electrolyte disorder doctors see in clinical practices.

Your body uses sodium in a variety of ways, such as:

  • fluid balance
  • blood pressure
  • nerves
  • muscles

Typical sodium levels in the blood are 135–145 milliequivalents per liter (mEq/L). If your sodium levels drop below 135 mEq/L, you have low sodium or hyponatremia.

Your body compensates for low sodium by sending more water to your cells, causing them to swell. This swelling is potentially dangerous, especially when it affects the brain.

Read all about electrolyte imbalance.

What are the symptoms of low sodium?

Symptoms typically vary from person to person, ranging from mild to severe. Some people do not experience any symptoms at all. Generally, someone with mildly low sodium will have few or no symptoms. People who experience severely low sodium or a rapid drop in levels are more likely to experience more intense symptoms.

If you experience a severe case of low sodium or a rapid drop in sodium levels, you may notice the following symptoms:

What causes low sodium?

One main cause of low sodium is too much water or fluid in your body. Excess fluid can cause your sodium levels to drop.

Some medications and conditions can cause your sodium levels to drop. Some of the other causes of low sodium include:

How do you treat low sodium?

Treatment for low sodium largely depends on the cause and severity. Your doctor may recommend lowering your fluid intake or adjusting your use of diuretics to balance your levels.

You may also need one or a combination of the following treatments:

  • sodium retaining medications
  • IV fluids
  • dialysis

Speak with your doctor to find the most effective treatment for your circumstances and to treat any underlying conditions.

What are the potential complications of low sodium?

Some complications can result from low sodium, especially without treatment. These complications include:

  • seizures
  • coma
  • altered mental status
  • rhabdomyolysis
  • osmotic demyelination syndrome
  • brain swelling
  • osteoporosis
  • instability when walking

Can you prevent low sodium?

You can help prevent your sodium levels from dropping too low by:

  • avoiding drinking excessive amounts of water
  • avoiding taking illegal substances, such as MDMA
  • getting treatment for any medical conditions
  • drinking sports drinks with electrolytes when doing intense exercises
  • speaking with your doctor about any medications you are taking

Learn the signs and symptoms of dehydration.


Low sodium is when the sodium levels in your blood drop too low. This can cause seizures, headaches, muscle cramps, and more. Without treatment, it can lead to more serious issues, such as brain swelling or coma.

The main cause of low sodium is an excess of water or fluid in your system. This results from many conditions, such as kidney or renal failure and congestive heart failure.

You can treat low sodium. If you experience any of the symptoms of low sodium, contact your doctor. They can recommend the most effective treatment plan for your situation and diagnose any other underlying conditions.

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Medical Reviewer: Jenneh Rishe, RN
Last Review Date: 2022 Jul 15
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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