Blood chloride testing is often ordered, along with other electrolytes, as part of a regular physical to screen for a variety of conditions. These tests may also be ordered to help diagnose the cause of signs and symptoms such as prolonged vomiting, diarrhea, weakness, and respiratory distress. If an electrolyte imbalance is detected, the doctor will look for and address the disease, condition, or medication causing the imbalance and may order electrolyte testing at regular intervals to monitor the effectiveness of treatment. If an acid-base imbalance is suspected, the doctor may also order blood gas tests to further evaluate the severity and cause of the imbalance.
In persons with too much base, urine chloride measurements can tell the doctor whether the cause is loss of salt (in cases of dehydration, vomiting, or use of diuretics, where urine chloride would be very low) or an excess of certain hormones such as cortisol or aldosterone (that can affect electrolyte excretion). Urine tests for chloride are also used, along with sodium, to monitor persons put on a low-salt diet. If sodium and chloride levels are high, the doctor knows that the patient is not following the diet.
Some of these tests may be ordered at regular intervals when a person has a disease or condition or is taking a medication that can cause an electrolyte imbalance. Electrolyte panels or basic metabolic panels are commonly used to monitor treatment of certain problems, including high blood pressure (hypertension), heart failure, and liver and kidney disease.
A urine chloride test may be performed along with a blood or urine sodium when evaluating the cause of low or high blood chloride levels. The doctor will look at whether the chloride measurement changes mirror those of the sodium. This helps the doctor determine if there is also an acid-base imbalance and helps to guide treatment.
An increased level of blood chloride (called hyperchloremia) usually indicates dehydration, but can also occur with other problems that cause high blood sodium, such as Cushing syndrome or kidney disease. Hyperchloremia also occurs when too much base is lost from the body (producing metabolic acidosis) or when a person hyperventilates (causing respiratory alkalosis).
A decreased level of blood chloride (called hypochloremia) occurs with any disorder that causes low blood sodium. Hypochloremia also occurs with congestive heart failure, prolonged vomiting or gastric suction, Addison disease, emphysema or other chronic lung diseases (causing respiratory acidosis), and with loss of acid from the body (called metabolic alkalosis).
An increased level of urine chloride can indicate dehydration, starvation, Addison disease, or increased salt intake. If both chloride and sodium levels are high in a person on a restricted salt diet, the person is not complying with the diet.
Drugs that affect sodium blood levels will also cause changes in chloride. In addition, swallowing large amounts of baking soda or substantially more than the recommended dosage of antacids can also cause low blood chloride.
This article was last reviewed on September 20, 2011. | This article was last modified on February 24, 2015.
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