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Cyanide (Total) in Serum or Plasma

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

This test measures the total amount of cyanide in your blood, which can be harmful if levels are too high. Cyanide is a toxic substance that can interfere with how your body uses oxygen.

Quick summary

["High cyanide levels may indicate poisoning or metabolic issues requiring urgent medical attention."]

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

Key facts at a glance

LOINC
13511-1
Short code
Cyanide Ascorbate Scn Bld Ql
Synonyms
Cyanide Ascorbate Scn Bld Ql
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Might Be Ordered

Your healthcare provider may order this test if you’ve been exposed to cyanide (e.g., through poisoning from chemicals, industrial accidents, or certain medications). It may also be used in cases of suspected metabolic disorders or to monitor treatment for conditions affecting cyanide metabolism.

What to Expect Before the Test

No special preparation is needed. You’ll have a small needle inserted into your arm or vein to draw blood. If you’re concerned about needles, let your lab staff know in advance.

What the Results Mean

Results are typically reported in milligrams per deciliter (mg/dL) or micrograms per deciliter (µg/dL). High levels may trigger immediate medical evaluation, while normal results suggest no acute poisoning.

Common Causes of Abnormal Results

Elevated cyanide levels can stem from poisoning (e.g., from cyanide-containing drugs, pesticides, or industrial exposures). Rarely, genetic disorders or certain medications may also affect cyanide metabolism.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Total Cyanide Level

Frequently asked questions

If your results show dangerously high cyanide levels, seek emergency care immediately. Symptoms of cyanide poisoning include shortness of breath, confusion, weakness, or even loss of consciousness.
This test helps doctors diagnose poisoning quickly and guide treatment, such as administering antidotes or supportive care.
What If I Have a History of Cyanide Exposure?
If you’ve had past exposure to cyanide (e.g., workplace or hobby-related), your provider may order this test more frequently to monitor your levels safely.
How Often Should I Get This Test?
Your provider will determine frequency based on your health, exposure history, and symptoms. Follow-up may be needed if you’re taking medications that interact with cyanide metabolism.
  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