Urine Sodium Tests- All You Need to Know

Introduction:

Sodium intake can influence blood pressure and proteinuria (the presence of urine in the blood). However, its association with chronic kidney disease (CKD) is not yet clear. Chronic diseases are the ones that have long-lasting effects on the life of the affected people. Examples of chronic diseases can include cardiovascular disease (CVD), chronic respiratory disease (CRD), cancer, and type 2 diabetes. Chronic diseases are rising globally, threatening their economy and quality of life. Such non-communicable diseases have become an increasing cause of death all around the globe. Studies show that a reduction in sodium intake can clinically produce a significant change in these conditions.

What Is Urine Sodium Test?

A test to examine whether a person’s sodium level in urine is average is called a urine sodium test. An elevated or reduced-sodium level can cause an underlying disease or condition. It can also be done after a blood sodium test with abnormal results. A sodium test helps to know if one is hydrated well. It also gives an idea of the functioning of the kidneys, especially in regulating electrolyte balance.

The body's proper functioning relies on sodium's essential role as an electrolyte. It helps the body to maintain fluid levels in the body. Sodium is present in almost all food one consumes daily, though there are differences in their levels. Increased consumption of sodium can make the kidneys work more to clear it. But sodium cannot be removed efficiently when the kidneys are not functioning correctly.

What Are the Other Names of Urine Sodium Tests?

Other names of urine sodium tests can include;

• Urinary 24-hour sodium test.

• Urine Na+ test.

What Are the Indications of Urine Sodium Tests?

Sodium is essential for the functioning of every cell in the body. It is also vital for the proper functioning of nerves and muscles. The amount of sodium in the urine can give an idea of the electrolyte imbalance in the body. It can also help to know if the kidneys are functioning correctly. It also helps to know if a person is hydrated properly or if one is drinking water properly. Indications of urine sodium tests can include;

• Hypertension (an elevation in the blood pressure levels).

• Pre-renal azotemia (a condition in which the kidneys are damaged and cannot remove nitrogen wastes properly.)

• Glomerulonephritis ( an inflammatory disorder of the kidneys).

• Hepatorenal Syndrome (HRS) is a form of progressive kidney failure observed in individuals who have experienced significant liver damage.

• Medullary cystic kidney disease ( a rare genetic condition where small cysts or fluid-filled sacs are found in the center of the kidneys).

• Acute kidney tubular necrosis ( a condition where the renal tubules are damaged or not functioning correctly).

How Is Urine Sodium Test Performed?

Usually, urine sodium tests are done in the laboratory itself. A container to provide the urine sample will be given. One would need to return the container with the sample. At times, the patient will be asked to collect different samples at different periods within twenty-four hours. The patient can go home and collect the urine samples at the required periods and return to the laboratory. The instructions given by the laboratory or the healthcare provider should be followed promptly to get accurate results.

How to Prepare for the Urine Sodium Test?

Certain drugs need to be stopped before taking urine sodium tests. These can include;

• Antibiotics like Streptomycin and Neomycin.

• Prostaglandins.

• Diuretics like Furesemide and Hydrochlorothiazide.

• Corticosteroids like Prednisolone.

• Non-steroidal anti-inflammatory drugs like Ibuprofen.

If one takes any supplements or over-the-counter drugs, it must be informed to the health care provider. They will advise on whether to continue or stop the drug. Never stop a drug without a physician’s consent. The sodium intake in food also can affect the test results. In cases where a very accurate result is required, a twenty-four-hour urine test would be suggested. This would be done over two days. The first urine on the first day is not collected. The rest of the urine is collected in specified containers every time. The last urine collection will be the first urine on the second day.

What Does the Result of the Urine Sodium Test Mean?

The normal urine sodium level is 20 mEq/L (milliequivalents per liter) for one-time urine sample tests. On the other hand, in a twenty-four urine test, the normal value results can range from 40 to 220 mEq/L per day. This can also be dependent on regular salt intake. The urine and blood sodium levels will be compared to determine the exact cause of kidney disease. Another reason for high sodium levels in urine and blood is that the body is losing more sodium than required.

Low levels of sodium in urine can be due to the following;

• Dehydration.

• Vomiting.

• Diarrhea or fluid loss.

• Kidney problems like glomerulonephritis.

• Increased ADH(anti-diuretic hormone) that causes sodium water retention. This usually happens in liver cirrhosis and heart failure.

• Increased production of hormones by adrenal glands (hyperaldosteronism).

Elevated sodium levels in urine can be due to the following;

• Use of diuretics.

• Increased consumption of salt in food.

• Impaired functioning of the adrenal glands.

• Inflammation of the kidneys.

• Vomiting

• Hypothyroidism.

• Bartter Syndrome (a condition in which the body does not reabsorb sodium).

What Are the Symptoms of an Increased or Decreased Sodium Levels?

The symptoms of decreased sodium levels can include;

• Fatigue.

• Nausea and vomiting.

• Headache.

• Loss of appetite

• Confusion or disorientation.

• Hallucination.

• Loss of consciousness.

An elevated level of sodium can cause;

• Thirst.

• Fatigue.

• Swelling in hands and feet.

• Weakness.

• Insomnia or sleeplessness.

• Increased heartbeat.

• Coma.

Conclusion:

Sodium intake influences blood pressure, and its impact on chronic kidney diseases is still unclear. In such scenarios, a urine sodium test enables one to measure the amount of sodium in the urine. It is usually suggested after a blood test that denotes an abnormal sodium level. An increased or decreased sodium level in the blood or urine can signify an underlying liver or kidney condition. The urine sodium test can be a one-time test or a twenty-four-hour test. The results can also depend on salt consumption in daily food.