What Is a Chloride Blood Test?

A chloride blood test, or serum chloride test, is used to measure the level of chloride in your blood. Chloride is an electrolyte, which is a mineral that carries an electrical charge when dissolved in water.

Chloride supports the balance of body fluids inside and outside your cells. It also strengthens proper blood volume, blood pressure, and the pH balance (acid-base balance) of your body fluids.

Factors such as vomiting, dehydration, or medical issues like kidney disease can affect chloride levels. Chloride levels that are too low or too high can make you feel ill. A chloride blood test can help your healthcare provider find the cause of these symptoms.

This article describes chloride blood test uses, techniques, and results. It includes everything you need to know about this test.

What Is a Chloride Blood Test Used For?

A chloride blood test checks your chloride level. It is typically performed as part of a general health evaluation. A chloride blood test can also help diagnose certain medical conditions like kidney or adrenal gland problems that interfere with the normal absorption or removal of chloride from your body.

When you are healthy, your body absorbs most of the sodium chloride, or table salt, you consume. Your intestines absorb chloride when you digest your food. Any excess chloride is removed through your urine. A medical problem can affect this process, making your chloride high or low.

Chloride works jointly with other electrolytes, such as potassium, sodium, and calcium. As a result, a chloride blood test is often ordered as part of an electrolyte panel to identify other types of electrolyte imbalances in addition to chloride. It can also be done with other blood tests, like a basic or comprehensive metabolic panel.

Who Needs a Chloride Blood Test?

You may need a chloride blood test if you have signs of an imbalance in your body's fluid level or acid-base balance. This may be linked to conditions that cause sodium losses or excess chloride levels.

Symptoms of these problems can include the following:

• Prolonged vomiting or diarrhea
• Hyperhidrosis (excessive sweating)
• Muscle weakness
• High blood pressure (hypertension)
• Fatigue
• Dehydration
• Breathing problems
• Muscle twitches or spasms
• Confusion
  

How to Prepare for a Chloride Blood Test

Generally, no special preparation is needed for a chloride blood test unless your healthcare provider instructs you to do otherwise. It is important that you advise your healthcare provider about any medications that you are taking. Do not stop or change your medications before the test unless your healthcare provider advises it.

Depending on your symptoms, your healthcare provider may order a urinalysis (urine test) or another test performed at the same time as a chloride blood test. If these tests require fasting, it will not affect the results of your chloride blood test.

Blood for a chloride blood test is collected in a medical setting such as your healthcare provider's office or a laboratory. Depending on where your blood sample is taken, a physician, nurse, or phlebotomist (an allied medical professional trained in taking blood samples for lab tests) may draw your blood sample.

The Chloride Blood Test Procedure

The procedure for a chloride blood test usually takes a few minutes. During the test, you remain seated.

The blood draw typically involves the following procedure:

• A medical professional cleans the injection site.
• A tourniquet is applied on your upper arm, above the vein to be used.
• You may be asked to squeeze your fist while a good vein is found.
• A medical professional injects a small needle into a vein in your arm.
• A small amount of blood is collected into a test tube or vial.

You may feel a slight sting or pressure when the needle is inserted or removed. Some people feel nothing at all.

Risks

A chloride blood test does not involve any major health risks for most people. However, any test that involves the extraction of blood using a needle can lead to the following problems:

• Bleeding
• Infection
• Bruising
• Light-headedness
• Slight stinging sensation at the site
• Soreness at the site

Reading the Results

Your chloride blood test results will include numbers that represent the normal range of chloride levels used by the lab where the test was taken. Every lab has a different range for what is normal.

Your test results may vary depending on age, gender, health history, and other personal characteristics. Normal chloride levels typically include the following ranges:

• For adults: 96 to 100 milliequivalents per liter (mEq/L)
• For children: 95 to 108 mEq/L
• For newborn babies: 96 to 113 mEq/L
  

What Happens After a Chloride Blood Test?

After a chloride blood test, your blood sample is sent to a medical laboratory. Your results are usually available within one or two days.

You can return to normal activities immediately after a chloride blood test unless you experience side effects like dizziness. If this occurs, you may have to sit calmly and have something to eat or drink before you leave the medical office or laboratory.

What Does a Low Chloride Level Mean?

Low chloride in blood, a condition known as hypochloremia, may be caused y one of the following conditions:

• Bartter syndrome (a condition in which your kidney has trouble reabsorbing salt and other electrolytes)
• Addison's disease (insufficient levels of the hormones cortisol and sometimes aldosterone due to primary adrenal insufficiency)
• Burns
• Congestive heart failure (your heart can't pump enough blood to meet your body's needs)
• Cushing's syndrome (too much cortisol in your body due to defective adrenal glands)
• Dehydration
• Excessive sweating
• Hyperaldosteronism (too much of the hormone aldosterone as a result of damaged adrenal glands)
• Metabolic alkalosis (a condition that raises the pH of blood above the normal range)
• Respiratory acidosis (your lungs don't clear enough carbon dioxide from your blood, making your blood too acidic)
• Syndrome of inappropriate antidiuretic hormone secretion (SIADH) (conditions that cause too much water to build up in your body)
• Ongoing vomiting

What Does High Chloride in Blood Mean?

High chloride in blood, a condition known as hyperchloremia, may be caused by one of the following conditions:

• Carbonic anhydrase inhibitors (medications used to treat glaucoma)
• Diarrhea
• Ethylene glycol poisoning
• Ketoacidosis (a buildup of acids in your blood)
• Kidney disease
• Lactic acidosis (a buildup of lactic acids in your blood)
• Metabolic acidosis (a buildup of acids in your body due to kidney disease or kidney failure)
• Methanol poisoning
• Distal or proximal renal tubular acidosis
• Respiratory alkalosis (low level of carbon dioxide in your blood due to breathing excessively)
• Salicylate toxicity (such as an overdose of aspirin)
• Ureteral diversion (urinary reconstruction to create a new way to pass urine out of your body)

When to Be Concerned About High or Low Results

High or low results from a chloride blood test that are outside normal levels do not always indicate a medical problem that needs treatment. The following factors can impact your chloride levels:

• Diet
• Excessive liquid consumption
• Certain medications like antacids
• A blood test error
• Gastrointestinal (GI) problems like diarrhea or vomiting that can cause a loss of fluids

Your healthcare provider is the best source of information for determining whether the results of your chloride blood test are a cause for concern. They use the results of your chloride blood test to determine whether your levels are within the normal range for your age and condition.

If you have high chloride levels or low chloride levels and your results indicate an underlying medical problem, you will be referred for further testing and confirmation of a diagnosis.

Summary

A chloride blood test measures the level of chloride in your blood. Normal chloride levels help maintain the proper balance of body fluids inside and outside your cells.

Results of a chloride blood test that show levels outside normal ranges are not always a cause for concern. While too high or too low levels can occur with certain health problems, external factors like diet and liquid consumption can also affect them.

Your healthcare provider can determine what your results mean and whether you need more testing or treatment.