Sodium urine test
Urinary 24 hours sodium; Urine Na+
The sodium urine test measures the amount of sodium in a certain amount of urine.
Sodium can also be measured in a blood sample .
Blood sample
The sodium blood test measures the amount of sodium in the blood. Sodium can also be measured using a urine test.
How the Test is Performed
After you provide a urine sample, it is tested in the lab. If needed, the health care provider may ask you to collect your urine at home over 24 hours . Your provider will tell you how to do this. Follow instructions exactly so that the results are accurate.
Collect your urine at home over 24 hour
The urine 24-hour volume test measures the amount of urine produced in a day. The amount of creatinine, protein, and other chemicals released into t...
How to Prepare for the Test
Your health care provider will ask you to temporarily stop taking any medicines that may affect the test result. Tell your provider about all the medicines you take, including:
- Corticosteroids
- Nonsteroidal anti-inflammatory drugs (NSAIDs)
- Prostaglandins (used to treat conditions such as glaucoma or stomach ulcers)
- Water pills (diuretics)
DO NOT stop taking any medicine before talking to your provider.
How the Test will Feel
The test involves only normal urination. There is no discomfort.
Why the Test is Performed
The test is often used to help determine the cause of an abnormal sodium blood level. It also checks whether your kidneys are removing sodium from the body. It may be used to diagnose or monitor many types of kidney diseases.
Normal Results
For adults, normal urine sodium values are generally 20 mEq/L in a random urine sample and 40 to 220 mEq/L per day (mEq/L/day). Your result depends on how much fluid and salt you take in.
The examples above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test result.
What Abnormal Results Mean
A higher than normal urine sodium level may be due to:
- Certain medicines, such as water pills (diuretics)
-
Low function of the
adrenal glands
Adrenal glands
The adrenal glands are two triangle-shaped glands. One gland is located on top of each kidney.
- Inflammation of the kidney that results in salt loss (salt-losing nephropathy)
- Too much salt in the diet
A lower than normal urine sodium level may be a sign of:
-
Adrenal glands
releasing too much hormone (
hyperaldosteronism
)
Adrenal glands
The adrenal glands are two triangle-shaped glands. One gland is located on top of each kidney.
Hyperaldosteronism
Hyperaldosteronism is a disorder in which the adrenal gland releases too much of the hormone aldosterone into the blood. Hyperaldosteronism can be pr...
- Not enough fluid in the body (dehydration)
- Diarrhea and fluid loss
-
Heart failure
Heart failure
Heart failure is a condition in which the heart is no longer able to pump oxygen-rich blood to the rest of the body efficiently. This causes symptom...
-
Kidney problems, such as chronic kidney disease or
kidney failure
Kidney failure
Acute kidney failure is the rapid (less than 2 days) loss of your kidneys' ability to remove waste and help balance fluids and electrolytes in your b...
-
Scarring of the liver (
cirrhosis
)
Cirrhosis
Cirrhosis is scarring of the liver and poor liver function. It is the last stage of chronic liver disease.
Risks
There are no risks with this test.
References
Batlle D, Chen S, Haque SK. Physiologic principles in the clinical evaluation of electrolyte, water, and acid-base disorders. In: Alpern RJ, Orson WM, Caplan M, eds. Seldin and Giebisch's The Kidney . 5th ed. Philadelphia, PA: Elsevier Saunders; 2013:chap 74.
Gerber GS, Brendler CB. Evaluation of the urologic patient: history, physical examination, and urinalysis. In: Wein AJ, Kavoussi LR, Novick AC, et al, eds. Campbell-Walsh Urology . 10th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 3.
McPherson RA, Ben-Ezra J. Basic examination of urine. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods . 22nd ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 28.
Review Date: 8/29/2015
Reviewed By: Laura J. Martin, MD, MPH, ABIM Board Certified in Internal Medicine and Hospice and Palliative Medicine, Atlanta, GA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.