The Sodium test contains 1 test with 1 biomarker.

Description: The sodium blood test is a test that measures levels of the electrolyte sodium in your blood’s serum.

Also Known As: Na Test, Sodium Serum Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: No preparation required

Average Processing Time: 1 to 2 days

When is a Sodium test ordered?

Most people's normal lab examination includes sodium tests as part of an electrolyte panel or a basic metabolic panel. These may be requested as part of an annual physical examination or when a person has non-specific health concerns.

When a person exhibits symptoms of low sodium, such as weakness, disorientation, or lethargy, a blood sodium test may be requested. If the sodium level drops too quickly, the individual may get weak and tired; in severe circumstances, the person may become confused or even coma. However, there may be no symptoms if the sodium level drops slowly. That is why, even if there are no symptoms, sodium levels are frequently monitored.

When a person shows signs of elevated sodium, such as thirst, dry mucous membranes, less frequent urine, muscle twitching, and/or agitation, sodium blood testing may be required. If the sodium level reaches to dangerously high levels, restlessness, illogical behavior, and coma or convulsions can occur.

Electrolytes are tested when intravenous fluids are administered or when dehydration is a risk. Electrolyte panels and basic metabolic panels are frequently requested to track the progress of treatment for illnesses such high blood pressure, heart failure, and liver and kidney disease.

What does a Sodium blood test check for?

Sodium is an electrolyte found in all body fluids and is essential for proper physiological functions such as nerve and muscle function. This test determines how much salt is present in the blood and/or urine.

Sodium, along with other electrolytes like potassium, chloride, and bicarbonate, aids cell activity and helps the body manage fluid levels. While sodium can be found in all physiological fluids, it is most concentrated in the blood and the fluid surrounding the body's cells. The kidneys control this extracellular sodium as well as all bodily water.

We receive sodium through table salt and, to a lesser extent, from most of the foods we eat. The majority of people consume enough salt. The body consumes what it needs and excretes the rest through the urine. The body tries to control salt levels in the blood within a fairly narrow range. It accomplishes this by:

  • Producing hormones that can alter the quantity of sodium excreted in urine
  • Generating a hormone that stops water loss
  • Controlling thirst; merely a 1% increase in blood sodium causes a person to become thirsty and drink water, bringing the sodium level back to normal.

A malfunction with one of these systems is frequently the cause of abnormal blood sodium levels. The water content of the body changes when the salt level in the blood fluctuates. These alterations are commonly coupled with either too little or too much fluid, resulting in leg edema.

Lab tests often ordered with a Sodium test:

  • Chloride
  • Potassium
  • Bicarbonate
  • Electrolyte
  • Basic Metabolic Panel (BMP)
  • Comprehensive Metabolic Panel (CMP)
  • Aldosterone
  • Renin
  • Renal Panel
  • ADH

Conditions where a Sodium test is recommended:

  • Kidney Disease
  • Dehydration
  • Adrenal Insufficiency
  • Addison Disease

How does my health care provider use a Sodium test?

A sodium blood test detects aberrant sodium concentrations, such as low sodium and excessive sodium. It's frequently utilized as part of a normal health checkup's electrolyte panel or basic metabolic panel.

Sodium is an electrolyte found in all body fluids and is essential for proper physiological functions such as nerve and muscle function. It aids regular cell activity and regulates the quantity of fluid in the body.

In persons who have dehydration, excess fluid, or a range of symptoms, a blood sodium test can be done to determine the reason and monitor treatment. Many disorders can cause elevated sodium levels in the blood. This test, along with others, may be ordered by a doctor to detect an electrolyte imbalance or symptoms of illness involving the brain, heart, lungs, thyroid gland, liver, kidney, or adrenal glands.

A blood sodium test may be performed to assess the success of treatment or to monitor persons using drugs that can impact sodium levels, such as diuretics, in people who have a known electrolyte imbalance.

What do my sodium test results mean?

A low sodium level in the blood could be caused by:

  • Too much sodium is lost, most usually due to diarrhea, vomiting, excessive perspiration, diuretics, kidney illness, or low cortisol, aldosterone, and sex hormone levels.
  • Excessive water consumption, which may occur during exercise
  • Heart failure, cirrhosis, and kidney disorders induce excess fluid accumulation in the body, resulting in protein loss or malnutrition. The body produces too much anti-diuretic hormone in a number of disorders, particularly those involving the brain and lungs, as well as many types of cancer and several medicines, leading a person to retain too much water in the body.

Reduced sodium consumption is rarely the cause of low blood sodium.

Losing too much water while not drinking enough nearly usually causes a high blood salt level. It could be related to a high salt intake without enough water, Cushing syndrome, or diabetes insipidus, a disorder characterized by a lack of ADH.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.

The following is a list of what is included in the item above. Click the test(s) below to view what biomarkers are measured along with an explanation of what the biomarker is measuring.


Sodium is a substance that the body needs to work properly it is vital to normal body processes, including nerve and muscle function
*Process times are an estimate and are not guaranteed. The lab may need additional time due to weather, holidays, confirmation/repeat testing, or equipment maintenance.

Customer Reviews