Liver Function (LFTs)

Ammonia

Normal range 15–45 µg/dL (11–32 µmol/L SI). Specimen: Plasma (on ice).

Also known as: NH3, blood ammonia.

15–45 µg/dLReference range

Reference range

Conventionalµg/dL

1545

SIµmol/L

1132

Specimen	Plasma (on ice)
Conventional range	15–45 µg/dL
SI range	11–32 µmol/L
Conversion factor	×0.587 (conventional → SI)
Panel	Liver Function (LFTs)

Convert any Ammonia result between units on the unit converter.

What is the normal range for Ammonia?

The standard teaching reference range for Ammonia is 15–45 µg/dL in conventional units, or 11–32 µmol/L in SI units. This value is measured in plasma (on ice).

Source: Adult reference values compiled from Pagana & Pagana, Mosby's Diagnostic and Laboratory Test Reference, and Fischbach & Dunning, A Manual of Laboratory and Diagnostic Tests. Reference ranges vary by laboratory, method, age, sex, and population — always use the range printed on the actual result.

Above the range

Common causes of a high Ammonia

Hepatic encephalopathy / liver failure
Reye syndrome
GI bleeding
Portosystemic shunting

At the bedside

Nursing considerations

Place the specimen on ice and transport immediately — levels rise on standing.
Correlate with mental status in liver disease, not the number alone.

Study aid

Your notes on Ammonia

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Same panel

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