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Chloride concentration in plasma or serum

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of chloride, a key electrolyte, in your blood plasma or serum. Chloride helps maintain fluid balance and supports nerve and muscle function.

Quick summary

["Chloride levels help assess hydration, acid-base balance, and kidney function."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
43158-5
Short code
Chlorine Free Wat-mCnc
Synonyms
Chlorine Free Wat-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your healthcare provider may order a chloride test to check for conditions affecting fluid balance, such as dehydration, kidney disease, or metabolic disorders. It can also help diagnose or monitor conditions like heart failure, severe vomiting, or excessive sweating.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast before the test if it’s part of a broader metabolic panel. Bring any medications or supplements you’re taking to your appointment.

How the Test Works

A blood sample is drawn from a vein, typically in your arm. The sample is sent to a lab where chloride levels are measured using a method like ion-selective electrode testing, which detects chloride ions in the plasma or serum.

What the Results Mean

Results are compared to standard reference ranges for your age and health status. Low chloride levels (hypochloremia) may indicate dehydration, kidney problems, or conditions like Addison’s disease. High levels (hyperchloremia) could suggest dehydration, kidney failure, or metabolic acidosis.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Chloride is essential for maintaining proper fluid balance in your body. Abnormal levels can signal underlying health issues, such as electrolyte imbalances, kidney dysfunction, or conditions affecting acid-base equilibrium. Regular monitoring is important for patients with chronic illnesses like heart disease or kidney disease.

Short name

Chloride

Frequently asked questions

What causes low chloride levels?
Low chloride levels may be caused by dehydration, excessive vomiting or diarrhea, kidney disease, or certain medications that alter fluid balance. It can also occur in conditions like Addison’s disease or severe burns.
What causes high chloride levels?
High chloride levels may result from dehydration, kidney failure, metabolic acidosis, or excessive use of certain medications. Rarely, it can be linked to genetic disorders or overuse of diuretics.
Can chloride levels change with diet?
Yes, diet can influence chloride levels. Foods high in salt (sodium chloride) may increase chloride levels, while low-sodium diets can lower them. However, chloride levels are primarily regulated by the body’s fluid balance and kidney function, not diet alone.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy