Ammonia (NH3) is a waste product naturally produced in the body, especially by the liver, kidneys and the intestines. It makes its way into the body through protein catabolism. The liver uses this ammonia and processes it to produce urea, which is less toxic. In case it is not processed and eliminated from the body, ammonia gets accumulated in the blood and becomes toxic to different organs, particularly the brain.
Why is the test performed?
An ammonia blood test may be ordered to assess the proper functioning of the liver and to monitor the effectiveness of treatment for liver cirrhosis. The test may also be ordered to help detect a childhood disorder – Reye syndrome, that causes liver and brain damage and predict its prognosis if it is diagnosed.
When is the test recommended?
An ammonia test may be recommended to test for the presence of a liver disease if the patient is suffering from sleepiness, mental changes and disorientation. An ammonia test may also be recommended in conjunction with other liver tests if an individual with a stable liver disease suddenly suffers from an acute illness. The test may also be recommended in newborns if the following symptoms are manifested within the first few days after birth:
How is the sample collected?
A blood sample is collected from a vein in the arm.
How to prepare for the test?
It is advisable to abstain from smoking cigarettes before the collection of the sample and to follow the instructions given by the doctor.