Think Ammonia: The Guidance for Healthcare Professionals

This information was updated February 2024 – we will endeavour to update regularly but more recent information may be available elsewhere


Hyperammonaemia is is a state in which ammonia levels in the blood are elevated. This is a time critical medical emergency with the risk of death and serious neurological damage. Symptoms can be nonspecific in the first instance, meaning that it can often be mistaken for more common conditions such as sepsis.

We’ve compiled these UK specific resources to help in the diagnosis, testing and treatment of hyperammonaemia to improve outcomes.

Guidance for neonates and children

Below are the latest guidelines for suspected hyperammonaemia in neonates and children.

Please consult your on call metabolic team for further guidance.

BIMDG Emergency Guidelines

The British Inherited Metabolic Disease Group have developed “child” guidelines for children and adolescents up to the end of puberty being managed on paediatric wards. These guidelines cover the diagnosis and early management of undiagnosed hyperammonaemia.

To access these guidelines click the button below, read the disclaimer and navigate to the Emergency Guidelines for Children Section. The guidelines can be found under “H”.

RCPCH Guidelines

The Royal College of Paedeatrics and Child Health include a guidance for when and how to test ammonia levels in their guidelines titled “The management of children and young people with an acute decrease in conscious level”. 

To access these guidelines click the button below:

Guidance for adults

Below are the guidelines for adults. 

Please consult your on call metabolic team for further guidance.

RCEM Guidelines

The Acute Behavioural Disturbance in Emergency Departments guidelines, published by the Royal College of Emergency Medicine, instucts healthcare professionals to conduct ammonia testing as part of investigations into decreased conciousness.

Testing for hyperammonaemia

Unsure of how to test for hyperammonaemia? Access the “Guidelines for the Investigation of Hyperammonaemia” from MetBioNet and contact your metabolic team if you require further guidance.

MetBioNet Guidelines

MetBioNet have published “Guidelines for the Investigation of Hyperammonaemia” which describe the differential diagnosis of hyperammonaemia, providing guidance to the non-specialist clinicians and laboratories on appropriate investigation, particularly with regards to inherited metabolic disorders.

To access these guidelines, click the button below to visit the MetBioNet best practice guidelines. Then scroll down the page until you reach the latest iteration of these guidelines.

Interested in having your resources for hyperammonaemia shared on this page?

We’re interested in offering the most up-to-date resources for hyperammonaemia to help healthcare professionals recognise the signs, test early and save lives.

If you’ve got resources you’d like sharing on this page or if you’re from a country outside of the UK, please feel free to contact us so we can discuss how to share your guidance.

Sound good? Email:

Poster: For healthcare professionals

This poster is designed for healthcare professionals and provides a guide on what to do if you suspect your patient is experiencing hyperammonaemia.

Click the button below  to access the downloadable PDF version. This can be downloaded by clicking “Download” at the top of the page after you’ve clicked the button.

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