Chloride Blood Test
Reviewed
Also called: CI, Serum chloride
A chloride blood test measures the amount of chloride in your blood. Chloride is an electrolyte that helps control fluid levels and the balance of acids and bases (pH) in your body. This test is often part of a routine blood screening or used to help monitor or diagnose conditions related to an acid or fluid imbalance.
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. Do not 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. Your provider will let you know if there are any special instructions.
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. 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
Your chloride levels may be reported as high or low. Reference ranges may vary; your provider will interpret your results based on your overall health and other factors.
- High chloride level (hyperchloremia): May be a sign of dehydration, kidney disease, or metabolic acidosis (too much acid in the blood). Limitation: Many things can affect chloride levels, such as drinking too much fluid or losing fluid from vomiting or diarrhea. Certain medicines, such as antacids, can also cause abnormal results. A high level does not always mean you have a medical problem that needs treatment. Next step: Talk to your provider to understand what your result means in your specific situation.
- Low chloride level (hypochloremia): May be a sign of heart failure, lung disease, Addison disease (adrenal glands not producing enough hormones), or metabolic alkalosis (too much base in the blood). Limitation: Many things can affect chloride levels, such as drinking too much fluid or losing fluid from vomiting or diarrhea. Certain medicines can also cause abnormal results. A low level does not always mean you have a medical problem that needs treatment. Next step: Talk to your provider to understand what your result means in your specific situation.
- 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
To learn what your results mean, talk with your provider. They will consider your symptoms, medical history, and other test results to determine if further evaluation or treatment is needed.
- 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?