The most important step in evaluating patients with abnormal liver enzyme levels is to take a thorough medical history and perform a complete medical examination. All the patient's medications, including over-the-counter drugs (OTC, and herbal remedies.Any history of blood transfusion (especially if done a long time ago when screening for donated blood was much less strict), history of intravenous (injection) or intranasal (snorting) drug use or needle sharing, tattoos, sexual contact with someone with possible viral hepatitis, alcohol consumption, , and possible consumption of contaminated food need to be questioned.Moreover, in addition to the liver tests (transaminases), other tests to screen the liver functions, such as a blood coagulation panel, albumin level, and total bilirubin level as well as a need to be measured.Screening for viral hepatitis is also routinely done to detect any possible active infections of the liver (acute or chronic active) or to determine immunity against these viruses either through prior infections or vaccination.In many instances, a doctor may also order an of the liver to assess the structure of the liver and the biliary tree as well to look for any gallstones that may be causing the liver disease. , Different foods and medicines can affect the results of liver function tests, and doctors may ask patients to avoid eating food and drink for 10-12 hours before the test., Common causes of elevated ALT and AST are viral liver infections, alcohol abuse, cirrhosis (from any chronic causes), and more. Normal levels of AST (SGOT) is about 5-40 units/liter of serum. Elevated levels of AST and ALT may signify the level of liver damage in a person..