What Is a Chloride Blood Test?
The chloride blood test, sometimes called a Cl test or serum chloride test, is a simple blood test that measures your chloride levels.
Why do chloride levels matter? You may have heard of electrolytes and their role in keeping you hydrated and healthy. One of the most important of these electrically charged minerals is chloride.
Chloride works with other electrolytes, such as sodium and potassium, to balance acids and bases (pH levels) in your body. It also helps move fluid and nutrients into and out of your cells. So, if your chloride levels drop, you can become sick and dehydrated. If your levels are too high, it may mean your kidneys aren’t working properly. That’s because your kidneys help control chloride levels in your blood.
The results of a chloride blood test can tell if your levels are normal or out of balance. This will help your doctor figure out where to look for the condition or medication that might be causing your imbalance.
Why Do I Need a Chloride Blood Test?
A doctor usually orders a chloride blood test with other blood tests when you’re having your cholesterol, blood sugar, and other electrolytes, such as sodium and potassium, checked.
If your doctor is concerned about the health of your heart or kidneys, a chloride test can help explain what might be wrong. Your chloride levels can drop if you have had bouts of vomiting or diarrhea. Diabetes can also sometimes cause chloride levels to increase.
If you’re having symptoms such as weakness, constant tiredness, or dehydration, your doctor may order a chloride test.
A doctor can also check your chloride levels with a urine (pee) test.
Chloride Blood Test Preparation
You don’t need to do anything special to prepare for a chloride blood test. But if it’s part of a metabolic panel, your doctor may tell you to avoid eating or drinking a few hours before the test.
How much fluid you drink before a chloride blood test could affect the results, so ask your doctor if you should change your fluid intake. Vomiting or diarrhea in the days before the test may lead to a lower chloride result.
Also, tell your doctor all the prescription and over-the-counter medications you take, along with any vitamins or supplements.
Some medications that may raise your chloride levels include:
- Ammonium chloride (used to treat people with low chloride levels in the blood and a condition called metabolic alkalosis)
- Cortisone (used to ease pain and inflammation)
- Estrogen
- Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and naproxen
You may not need to change your medication routine. It’s just important that your doctor knows what you take, even if it’s aspirin for a headache.
If you’re scheduled for a urine chloride test, avoid alcohol for at least 24 hours before giving a sample.
What Happens During a Chloride Blood Test?
Testing the chloride levels in your blood is usually painless and takes little time. But the information it gives your doctor can help you avoid some painful and serious health problems down the road.
To get the test, you’ll have a blood sample taken at your doctor’s office or a lab. A nurse or lab tech will insert a needle, usually into a vein in your arm. They’ll use it to collect a small amount of blood into a vial or test tube. The whole procedure generally takes less than five minutes.
Your arm may be a little sore where the blood was drawn. Some people become lightheaded for a few moments.
You should be able to get your test results within a few days. It may be sooner if your doctor has ordered that the results be checked at once.
Chloride Blood Test Results
Your doctor can help you understand what the results of your chloride blood test mean. Keep in mind that things such as your fluid intake and medications can affect your chloride levels.
Nurse practitioner Joy King, president-elect of the Georgia Nurses Association, says trends over time are more important than the results of one blood test.
“Rather than reacting to a single result, we look at patterns, especially when the patient is otherwise feeling well,” King says. “A retest, paired with a review of lifestyle, nutrition, and medication history, gives a doctor a clearer picture of what is really going on.”
What is a safe level of chloride?
The normal range for chloride in your blood is often considered to be between 96 and 106 milliequivalents per liter (mEq/L). But labs vary in their definition of the normal range.
What does a high chloride level mean?
Because what’s considered a normal chloride level can differ by lab, “a specific value cannot be pinpointed as to what is too high,” says Pamela Kelley, a nurse practitioner with First Georgia Physicians Group in Fayetteville, Ga. “However, a chloride level that is above normal is concerning when a patient is symptomatic or there are other markedly abnormal labs.”
If your chloride levels in blood are higher than normal, it could point to kidney problems, such as renal tubular acidosis (when your kidneys aren’t removing enough acids from your blood).
They can also be a sign of:
- Dehydration
- Cushing’s syndrome, a hormonal disorder
- Metabolic alkalosis, in which acids build up in your blood
- Respiratory alkalosis, in which your blood pH is too high
What does a low chloride level mean?
There are several possible causes for lower-than-normal chloride levels in blood, including common and temporary problems such as vomiting and dehydration. Among the more serious causes are:
- Congestive heart failure (when your heart muscle is weakened and can’t pump blood to your body as well as it should)
- Burns
- Addison’s disease (when your adrenal glands don’t make enough of certain hormones)
- Metabolic alkalosis
- Hyperaldosteronism (a condition that can cause high blood pressure and weakness)
- Chronic (ongoing) lung disease
Takeaways
The chloride blood test measures levels of chloride in a sample of your blood. Chloride is an electrolyte that helps balance acids and bases in your body and move fluids to and from your cells. Low levels can indicate conditions ranging from dehydration to congestive heart failure. High levels could be a sign of kidney issues or a side effect of medications you take. If your results are outside the normal range, your doctor can find out the cause and suggest treatment if needed.
Chloride Blood Test FAQs
What does chloride mean in a blood test?
Doctors measure chloride in blood tests because it’s an electrolyte. Electrolytes are minerals that help maintain the balance of acids and bases, as well as fluids, in your body. Too much or too little chloride could point to a medical issue. It could also be a sign of dehydration or excess fluid intake, or a result of medications you take.
What level of chloride indicates kidney failure?
Doctors don’t diagnose kidney failure by chloride blood tests alone. Chloride levels that are higher than normal can sometimes indicate that you have a kidney problem. But several other things can also cause high blood chloride levels.
How can I reduce chloride in blood?
There are many ways to reduce your blood chloride levels, but it depends on what’s causing them. This might include:
- Eating less salt
- Drinking plenty of fluids
- Avoiding excessive laxative use
- Changing medications or dosages
If you have diabetes or chronic kidney disease, it’s important to control your blood pressure, blood sugar, and cholesterol.