Chloride Test

Chloride ions are responsible for many vital functions in the body. They are often associated with sodium ions, and hence any imbalance in sodium concentration can also result in chloride ion imbalance. In the case of the following conditions, the doctor may advise a chloride test.

• Weakness
• Deep rapid breathing or shallow breathing 
• Lethargy
• Stupor, which may further progress into coma
• Hypertonicity of muscles
• Tetany
• Kidney dysfunction
• Muscle spasms
• Hypotension
• Diarrhoea
• Vomiting

It is a simple test that does not require any special preparation by the patient. Fasting is not required before the test. 
Urine testing can be done at random or over a period of 24 hours. The laboratory pathologist will instruct you on how to collect urine for 24 hours and will provide suitable collection containers too.

Chloride blood test: It is a simple procedure, in which, a technician will insert a small needle into your forearm and collect around 7 millilitres (mL) of the sample in a green-capped tube preferably without tying a tourniquet. You may experience slight pain or a stinging sensation as the needle goes into the vein but otherwise, this test does not have any risks. 

Chloride urine test: You will have to begin the 24-hour urine collection at 7:00 a.m. in the morning and refrigerate the samples collected over the entire period of 24 hours. The pathologist and doctor will instruct you about noting the beginning and end timings on the sample container. After the last urine sample is collected at the end of 24 hours, the samples are sent for analysis.

Normal results

Chloride Blood test: A chloride concentration of 90-106 milliequivalents per litre (mEq/L) or 90-106 millimoles per litre (mmol/L) in blood serum is considered normal.
Chloride urine test: For 24-hour chloride concentration in urine, the following results are considered normal:

In an adult: 140-250 mEq/24 hours or 140-250 mmol/day
In a child aged <6 years old: 15-40 mEq/24 hours or 15-40 mmol/day
In a child aged 10-14 years old: 64-176 mEq/24 hours or 64-176 mmol/day

Test results depend on salt intake and perspiration in an individual and hence vary greatly. Different laboratories may have different standard values.

Abnormal results: Values greater or lesser than normal values are considered abnormal. Abnormal results may be attributed to the breakdown of red blood cells in the blood sample or the intake of certain drugs. A condition marked by a greater than the normal value of chloride in the blood or urine is termed as hyperchloraemia, while lesser than normal values are termed as hypochloraemia. 

Administration of excess chloride infusion, excessive salt intake and metabolic acidosis may lead to hyperchloraemia. Severe dehydration also leads to temporary elevation of chloride concentration. Hyperchloraemia may be an indication of the following conditions:

• Acute renal failure
• Alcoholism
• Anaemia
• Cushing syndrome
• Hyperparathyroidism
• Diabetes insipidus
• Adrenocortical insufficiency
• Multiple myelomas
• Respiratory alkalosis

Chloride levels in the blood and urine might fall due to excessive sweating, vomiting and certain exogenous and endogenous corticosteroids. Patients admitted for acute decompensated heart failure also show low chloride levels. Hypochloraemia indicates the following conditions:

• Diarrhoea
• Addison’s disease
• Metabolic alkalosis
• Acute infections
• Burns
• Ulcerative colitis
• Low sodium and potassium levels
• Chronic renal failure

In conclusion, it can be said that chloride levels below or above normal can lead to serious health problems, and hence prompt and correct diagnosis using a simple and easy laboratory test can help decide the treatment.

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. The above information is provided from a purely educational point of view and is in no way a substitute for medical advice by a qualified doctor.