Chloride Blood Test
Reviewed
Also called: CI, Serum chloride
A chloride blood test measures the amount of chloride in your blood. Chloride is a type of electrolyte.
Specimen: Blood (from a vein in your arm)
Why this test may be ordered
- As part of a routine blood screening to check your general health
- To help monitor or diagnose conditions related to an imbalance of acids or fluids in your body
- If you have symptoms of an acid or fluid imbalance, such as vomiting over a long period, diarrhea, fatigue, weakness, dehydration, or trouble breathing
Preparation and collection
You may need to stop taking certain medicines before this test, so tell your provider about everything you take. But don't stop taking any medicines unless your provider tells you to. If your provider has ordered other blood tests, you may need to fast (not eat or drink) for several hours before the test.
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
Understanding results
There are many reasons why your chloride levels may not be in the normal range.
- High chloride (hyperchloremia): High levels of chloride (hyperchloremia) may be a sign of: Dehydration. Metabolic acidosis, a condition in which you have too much acid in your blood. Limitation: If your chloride levels are not in the normal range, it doesn't always mean you have a medical problem that needs treatment. Also, certain medicines, such as antacids, can cause abnormal results. Next step: To learn what your results mean, talk with your provider.
- Low chloride (hypochloremia): Low levels of chloride (hypochloremia) may be a sign of: Heart failure. Addison disease, a condition in which your body's adrenal glands don't produce enough of certain types of hormones. Metabolic alkalosis, a condition in which you have too much base in your blood. Limitation: Many things can affect your chloride levels, such as drinking too much fluid or losing fluid because of vomiting or diarrhea. Next step: To learn what your results mean, talk with your provider.
- Many factors can affect chloride levels, including fluid intake, fluid loss from vomiting or diarrhea, and certain medicines (such as antacids).
- Abnormal chloride levels do not always indicate a medical problem that needs treatment.
- Reference ranges may vary between laboratories; your provider will interpret your results.
What to do next
Your provider may also recommend a urine chloride test to get more information about your chloride levels. To learn what your results mean, talk with your provider.
- What do my chloride levels indicate about my overall health?
- Do I need any additional tests, such as a urine chloride test or an electrolyte panel?
- Could any medicines I am taking affect my chloride levels?
- What symptoms should I watch for that might suggest an acid or fluid imbalance?
- How often should I have my chloride levels checked?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.