The reason for taking liver test levels is to check how well the liver creates a protein called albumin and how well it disposes a waste product of the blood called bilirubin. Liver test levels help determine if the liver is functioning properly, according to Healthline.
The test is done by taking a sample of blood from an arm vein. When the liver is not working properly, it can lead to high levels of bilirubin or low levels of albumin in the blood, claims Healthline. Symptoms of liver disorder include nausea, vomiting, diarrhea, fatigue and abdominal pain. A damaged liver can lead to severe sickness or death.