Serum Sodium (Na) Test

The Sodium Serum test is conducted to determine the current level of sodium in the body.

Sodium is an important element in the human body and is responsible for maintaining the body in a healthy state. With abnormal levels of sodium, the body can often develop a number of health disorders like hypertension.

The Sodium Serum test is usually conducted as a part of a group of tests to measure the levels of different substances in the blood. These tests are together called Basic Metabolic Panel (BMP) and Electrolyte Panel test. These tests evaluate the acid-to-base balance, the level of electrolytes and the glucose level in the blood.

Sodium helps in maintaining the body's cardiovascular and nervous systems. So, it is very important for the body to have just the appropriate amount of sodium in the blood because any abnormality can have serious effects.

Doctors prescribe the Sodium Serum test as a part of your routine health checkup or when you have a condition that can adversely affect the level of sodium in your body. (For instance, when you are taking medication, etc.)

There have been many studies noting that Indians consume way more sodium than what is recommended as the daily sodium intake by the World Health Organization. The Indian diet is rich in salt and so, the country’s population is largely found overconsuming sodium.

Over a prolonged period, if excess sodium levels go untreated, the body can develop a number of issues, like the disrupted functioning of the nervous system and hypertension.

Other names of Sodium Serum test

• Serum Sodium Test
• Sodium Test
• Na+ test

What does the Sodium Serum test detect/measure and who is this prescribed for?

The Sodium Serum test is suggested for:

• People who have gone through serious physical injury or surgery and have consumed a lot of medications. In such a situation, excessive medicines can disrupt the sodium-to-water balance in the body.
• People who take intravenous fluids. This can be for many reasons and not just an injury requiring hospital admission. Many people have preexisting health conditions that require a drip (IV). To make sure that the body’s sodium level is not adversely affected by injecting fluids into the veins, the doctor may suggest testing for sodium.

• People who regularly intake large amounts of salt have developed Hypernatremia.

Further, people who show any of the following symptoms of abnormal sodium levels in the body (maybe too much or too low sodium) are also advised to get the Sodium Serum test done:

• A rise in blood pressure
• Nausea
• Dizziness
• Exhaustion
• Vomiting
• Pain in muscles
• Having a hormone imbalance and taking medications for it
• Swellings in various parts of the body
• Frequent thirstiness
• Insomnia
• Confusion

These symptoms can prompt your healthcare professional to suggest a Sodium Serum test for the diagnosis of any serious health issues like hypertension, abnormal blood pressure, etc.

Sodium Serum blood test results should be interpreted on the basis of the following levels:

For the Sodium Serum Urine Test, in the case of a one-time urine sample, the normal sodium value in the urine should be around 20 mmol/L.

For the 24-hour sodium serum urine test, the normal range is 40 to 220 mmol/L per day.

When the sodium levels are lower than normal, the person may be suffering from a condition called Hyponatremia. This condition is associated with:

1. The adrenal glands do not produce sufficient hormones (termed Addison Disease).
2. Conditions of dehydration, vomiting and diarrhoea.
3. A build-up of waste products from a fat breakdown in the urine.
4. An increase in the total body water is mainly seen in people with heart failure, kidney diseases or some liver disorders.
5. Use of medicines such as diuretics (water pills), morphine and SSRI antidepressants.

When the sodium levels are higher than normal, the person may be suffering from a condition called Hypernatremia. This is associated with:

1. Issues with the adrenal gland like Cushing’s syndrome or hyperaldosteronism.
2. People have the type of diabetes in which kidneys are not able to conserve water or Diabetes Insipidus.
3. An increased fluid loss due to excessive sweating, burns, diarrhoea or the use of diuretics.
4. Individuals consuming too much salt or sodium bicarbonate in their diet.
5. Persons using specific medicines like birth control pills, lithium, laxatives, corticosteroids and NSAIDs like Ibuprofen.

There are two Sodium Serum test sample types: Sodium Serum urine test and Sodium Serum blood test.

The urine test is suitable for determining if you are well hydrated and if your kidneys are functioning well. In contrast, the doctor may suggest the Sodium Serum blood test if they want a more accurate idea of the sodium level in the blood.

Test Preparation

To prepare for the Sodium Serum test, you will not be required to fast before your Sodium Serum blood test sample is taken.

In the case of the Sodium urine test, you will have to check with your doctor about what to eat because your diet can affect the body’s sodium level.

In addition to the diet, you may also be suggested to stop taking some specific medications right before giving your sample. These medications will only be the ones that can temporarily cause a hike or decline in the sodium level in the body.

To avoid the masking of the actual sodium level due to the use of such medicines, you might be advised not to take that medicine a day before the test sample will be collected. However, you should not stop consuming any of your regular medicines (in case you take any) before consulting with your healthcare professional.

There will not be much that you will have to prepare for during and after the Sodium Serum test. You will be required to give either your blood sample or urine sample to the laboratory professional. However, you may take advice from your doctor before resuming your medications after the test.

Test inclusions: What parameters are included?

The two kinds of blood tests that determine the sodium levels in the blood have different testing parameters:

• Electrolyte Panel Test

Electrolytes are important minerals found in the body, responsible for maintaining a healthy water balance in the body and ensuring that the body’s pH level is maintained.

The Electrolyte Panel test includes testing for Sodium, Potassium, Chloride and Bicarbonate. All these electrolytes have an instrumental role in ensuring that the body is functioning at its best.

• Basic Metabolic Panel Test

The Basic Metabolic Panel test measures eight factors, including Sodium, Glucose, Calcium, Chloride, Potassium, Creatinine, Bicarbonate and Blood Urea Nitrogen.

Doctors prescribe this test for the purpose of screening for any health problem, diagnosis of health issues on the basis of symptoms and monitoring any existing health problems.

The Sodium Serum urine test is taken in either of two ways: a normal one-time sample or a 24-hours sample. The 24-hour test will require you to collect a sample every time you urinate in a period of 24 hours. This test will help in recording results in accordance with the dietary sodium intake and is more accurate than the normal urine test.

How frequently should you take this test?

The sodium test is usually a part of your routine health checkup. It is best to consult your doctor to know when you should get your general health checkup done.

In cases of injury where the person has to take extra medication and injection of fluids, the doctor may suggest they get the Sodium Serum test frequently to keep regular tabs on the blood sodium level.

Hypernatremia, Hyponatremia, People undergoing surgery