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Serum or Plasma Mass Concentration of Ammonia (NH₃)

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

This test measures the amount of ammonia, a waste product, in your blood or plasma. Ammonia is produced when proteins break down in your body and can build up if your liver isn’t working properly.

Quick summary

["Ammonia levels help check liver function and detect potential liver disease or metabolic issues."]

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

Key facts at a glance

LOINC
106983-0
Short code
TEX101 Smn IA-mCnc
Synonyms
TEX101 Smn IA-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
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 doctor may order this test if you have symptoms like confusion, fatigue, or nausea, or if they suspect liver problems, kidney issues, or metabolic disorders. It can also be part of routine monitoring for certain conditions.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the test if it involves a blood draw. Avoid foods high in protein (like red meat) for that period if instructed.

How the Test Works

A small blood sample is taken from a vein in your arm. The sample is sent to a lab where it’s analyzed to measure ammonia levels using a specialized method, often automated and highly sensitive.

What the Results Mean

High ammonia levels may indicate liver disease, kidney failure, or other metabolic disorders. Low levels are less common but could suggest certain genetic or nutritional deficiencies. Your doctor will interpret results in the context of your overall health.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Ammonia Level

Frequently asked questions

What causes high ammonia levels?
High ammonia levels can result from liver disease (such as cirrhosis or hepatitis), kidney problems, certain metabolic disorders (like urea cycle defects), or conditions that slow digestion (e.g., bowel obstruction). Dietary factors, like excessive protein intake, can also temporarily raise levels.
What causes low ammonia levels?
Low ammonia levels are rare but may occur in people with severe malnutrition, certain genetic disorders affecting protein metabolism, or after liver surgery. Rarely, it can be linked to medications or metabolic imbalances.
How often should I get this test?
Your doctor will determine how often you need this test based on your medical history, symptoms, and other tests. For example, people with liver disease may need monitoring more frequently than others.
  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