Low Sodium Causes and Symptoms: Ways to Normalize Sodium Levels

Sodium is an important electrolyte in the body. It has several vital functions to play such as balancing water inside and outside of the cell. Stabilizing blood pressure and maintaining healthy function of muscles and nerves. When sodium level in blood decreases the condition in medical terminology is called hyponatremia. This occurs when there is imbalance between water and sodium in the body.

It can be due to two reasons. Firstly there may be excess of water in the body or secondly there is very low amount of sodium in the blood. Both these factors are responsible for hyponatremia. The normal value of sodium in the body must be between 135 and 145 mEq/L. Person is considered to have low sodium when his blood sodium level goes below 135 mEq/ L.


Low sodium level in blood can result from increased amount of water or fluid in the body or due to lack of adequate sodium level in the body. If there is too much of fluid or water accumulation in the body, it dilutes the normal sodium level leading to low sodium.

In kidney failure or in congestive cardiac failure, there is excess accumulation of fluid in the body. This may cause dilution of sodium level. Hence patients suffering from both these conditions must be careful about their sodium level in blood. Rise of anti diuretic hormone in certain disease can also lead to low sodium level due to retention of water. If you drink too much of water while performing strenuous exercise without adequately replacing sodium and other salts, you may suffer from electrolyte imbalance.

Low sodium can result when there is inadequate amount of sodium in the body. This may occur if sodium is lost in excess as in case of severe diarrhea and vomiting together with fluid.

Low sodium level can also develop in certain medical conditions such as hypothyroidism, adrenal insufficiency and cirrhosis of liver.

Medications such as diuretics, vasopressin and various other drugs can cause low sodium level.

Risk factors include:

  • Elderly age group
  • People taking diuretics
  • People performing high intensity exercise such as athletes etc.
  • People living in extreme warm climate. Low sodium level in them can occur as a result of dehydration.
  • Persons who are on low salt diet.
  • Patient suffering from kidney and heart failure.


When there is low level of sodium in the body and too much of water, the cells become swollen as water enters into it. The severity of hyponatremia depends on the amount of fluid retention. Low sodium can be acute or chronic. Acute hyponatremia is sometimes deadly and needs urgent medical attention. Acute hyponatremia results instant edema in the brain. When blood sodium level drops gradually the symptoms are less severe. Symptoms of low sodium level are as follows:

  • History of patients suffering from diarrhea and vomiting.
  • Headaches
  • Disorientation
  • Cramps in calf and other muscles
  • Weakness in muscles
  • Confused state of mind
  • Lethargic
  • Increased irritability
  • In severe cases when brain swelling develops patient may suffer from seizures, coma and even death.

Diagnosis and treatment:

For diagnosis of hyponatremia or low sodium level, blood test is performed. Blood test will confirm low sodium level in blood. The result of test is less than 135 mEq/L. Normal value is 135-145 mEq/L. Often together with sodium other electrolytes are also measured in blood. These electrolytes include chloride and potassium.

Mild low sodium of long standing duration may only require dietary adjustment, change in lifestyle and medications. In case of severe hyponatremia, patient needs immediate hospitalization for intravenous administration of fluids and electrolytes. Much of the salt we get from the food that we prepare. We all add salt in our food preparations. Besides some small amount we also get from meat, milk, celery etc.

The underlying condition must also be addressed that triggers low sodium level in the body. Person suffering from kidney failure, congestive heart failure, cirrhosis of liver, hypothyroidism etc needs to be treated for those conditions.