First Time User? Enroll now.
COVID-19: Vaccine information, visitor restrictions, testing, treatment, and additional resources
Home > Health Library > Chloride (Cl) Test
A chloride test measures the level of chloride in your blood or urine. Chloride is one of the most important electrolytes in the blood. It helps keep the amount of fluid inside and outside of your cells in balance. It also helps maintain proper blood volume, blood pressure, and pH of your body fluids. Tests for sodium, potassium, and bicarbonate are usually done at the same time as a blood test for chloride.
Most of the chloride in your body comes from the salt (sodium chloride) you eat. Chloride is absorbed by your intestines when you digest food. Extra chloride leaves your body in your urine.
Sometimes a test for chloride can be done on a one-time random sample of urine or on a sample of all your urine collected over a 24-hour period (called a 24-hour urine sample). This can help find out how much chloride is leaving your body in your urine.
Chloride can also be measured in skin sweat to test for cystic fibrosis.
A test for chloride may be done to:
In general, there's nothing you have to do before this test, unless your doctor tells you to.
A health professional uses a needle to take a blood sample, usually from the arm.
This test is usually done at home. You must collect all the urine you produce in a 24-hour period.
You collect your urine for a period of time, such as over 4 or 24 hours. Your doctor will give you a large container that holds about 1 gallon. You will use the container to collect your urine.
But don't save this urine. Write down the time you began.
Each time you urinate during this time period, collect your urine in a small, clean container. Then pour the urine into the large container. Don't touch the inside of either container with your fingers.
Add this urine to the large container. Then write down the time.
When a blood sample is taken, you may feel nothing at all from the needle. Or you might feel a quick sting or pinch.
This test usually doesn't cause any pain or discomfort.
There is very little chance of having a problem from this test. When a blood sample is taken, a small bruise may form at the site.
There is very little chance of having a problem from this test.
Each lab has a different range for what's normal. Your lab report should show the range that your lab uses for each test. The normal range is just a guide. Your doctor will also look at your results based on your age, health, and other factors. A value that isn't in the normal range may still be normal for you.
High chloride levels may be caused by:
Low chloride levels may be caused by:
Current as of:
June 17, 2021
Author: Healthwise StaffMedical Review: E. Gregory Thompson MD - Internal MedicineAdam Husney MD - Family MedicineMartin J. Gabica MD - Family Medicine
Current as of: June 17, 2021
Author: Healthwise Staff
Medical Review:E. Gregory Thompson MD - Internal Medicine & Adam Husney MD - Family Medicine & Martin J. Gabica MD - Family Medicine
To learn more about Healthwise, visit Healthwise.org.
© 1995-2022 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.