What is a Chloride Blood Test?
Chloride is an electrolyte that helps maintain proper fluid and acid/base balance in your body. The blood test is often performed as a part of a comprehensive metabolic panel. A metabolic panel also measures your levels of other electrolytes, including carbon dioxide, potassium, and sodium. The proper balance of these electrolytes is critical for the normal functioning of the muscles, heart, and nerves. It is also essential for normal fluid absorption and excretion.
This test is used to detect abnormal blood chloride levels in order to diagnose a variety of health conditions, including alkalosis (when your blood is either too alkaline or basic) and acidosis (when it is too acidic). It can also be used to monitor patients with high blood pressure, heart failure, kidney disease, or liver disease. These conditions can cause an electrolyte imbalance.
Symptoms that may indicate a chloride imbalance include:
- excessive fatigue
- muscle weakness
- breathing problems
- frequent vomiting
- prolonged diarrhea
- high blood pressure
Preparing for the Test
For accurate results, you will be instructed not to drink or eat anything during the eight hours leading up to the test. Hormones, nonsteroidal anti-inflammatory drugs (NSAIDs), and diuretics can affect your test results, so you should avoid taking them if you can.
Tell your doctor about any medications you take, whether they are over-the-counter or prescription drugs. You may need to stop taking these medications before the test.
How the Test Is Administered
During the test, a lab technician will draw blood from a vein on the inside of your elbow or the back of your hand. The technician will clean the area with antiseptic to help prevent infection. Then, your arm will be wrapped with an elastic band to allow the veins to fill with blood and make them more visible. The technician will draw a blood sample using a small needle and then cover the puncture site with gauze or a bandage.
The process takes just a few minutes. The lab will test the blood sample within three to five days, and your doctor will call you with the results.
Drawing blood is a routine laboratory test, and there are very few risks involved. Rare side effects include:
- excessive bleeding
- dizziness or fainting
- blood accumulation beneath the skin (hematoma)
- infection at the puncture site
Infections rarely occur if the lab technician follows proper procedure. Call your doctor right away if the puncture doesn’t close on its own or if you start to experience pain and swelling in the area.
Interpreting the Test Results
According to the National Institutes of Health, the normal range for blood chloride is between 96 and 106 milliequivalents of chloride per liter of blood (mEq/L). Above-normal levels indicate hyperchloremia (too much chloride in your blood), while low levels indicate that you have hypochloremia (too little chloride in your blood).
Hyperchloremia may be attributed to:
- medications used to treat glaucoma
- bromide poisoning
- metabolic or renal acidosis (when your body produces too much acid or your kidneys do not effectively remove acid from your body)
- respiratory alkalosis (low levels of carbon dioxide on your blood)
Hypochloremia can be caused by:
- heart failure
- excessive sweating
- excessive vomiting
- congestive heart failure
- metabolic alkalosis (when your tissues are too basic or alkaline)
- respiratory acidosis (when your lungs cannot remove enough carbon dioxide from your body)
- Addison’s disease (when the adrenal glands in which sit atop your kidneys do not produce enough of the hormones that are essential to maintaining normal electrolyte balance)
Following Up After Receiving Your Test Results
Your follow-up will depend on whether your blood test indicates an abnormally high or low blood chloride level. Electrolyte abnormalities unassociated with serious underlying heart, kidney or liver disease can usually be corrected by avoiding certain drugs that may interfere with absorption of these essential substances. Your doctor should be informed of all medications or drugs you take (prescribed or over-the-counter) and he or she will advise you of which medications you must discontinue.
The more serious health conditions—such as heart, kidney, or liver disease—can be related to abnormal blood chloride levels and early medical intervention may improve the prognosis in these cases. Be sure to follow your doctor’s treatment recommendations.