A small amount of blood may be taken and tested to check one or more of the following:
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Alpha fetoprotein (AFP). This is normally high in newborns. But high levels in the blood of an older child can be a sign of liver cancer.
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Albumin. This is a protein made by the liver. It can be measured with a blood test. When a person has liver disease, the level of albumin in the blood (serum albumin) is often low.
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Alkaline phosphatase (AP). This is an enzyme made in the liver and bone. It’s measured with a blood test. A high level may mean there’s a problem with the bile ducts in the liver.
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Alanine aminotransferase (ALT). This is an enzyme made by the liver. When the liver is damaged, ALT leaks into the blood. If a blood test finds a high level of ALT, this can be a sign of liver problems, such as inflammation, scarring, or a tumor.
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Ammonia. This is a harmful substance left behind in the blood after digestion. Normally, the liver removes ammonia from the blood and turns it into urea. This leaves the body with urine. If a blood test shows that the ammonia level is too high, this process isn’t happening as it should.
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Aspartate aminotransferase (AST). This is another enzyme made by the liver and also made by other organs. High levels suggest liver injury, especially if the ALT level is also high.
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Bilirubin. This is a yellow substance made when the body breaks down red blood cells. It’s collected by the liver to be sent out of the body with stool. When something is wrong with the liver or bile ducts, bilirubin may build up in the body. This causes yellowing of the skin and the whites of the eyes (jaundice). Two measurements may be taken: total bilirubin and direct bilirubin. A high total bilirubin level means the liver isn’t breaking down bilirubin. A high direct bilirubin level suggests a blockage in the bile ducts.
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Complete blood count (CBC). This is a test that measures all the parts of the blood: red blood cells, white blood cells, and platelets. Problems with these counts can mean infection or illness. They can also be a sign of a problem with the spleen. This is an organ close to the liver that can be affected by liver disease.
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Essential fatty acids (EFAs). These are important nutrients. EFA levels may be lower when the liver is diseased. This is because the liver can’t absorb and transport EFAs as it should.
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Gamma-glutamyl transpeptidase (GGT). This is an enzyme that’s often measured along with other enzymes to gauge liver problems. GGT is measured with a blood test. If AP and GGT are both high, this is a sign that the bile ducts in the liver may be diseased or blocked.
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Glucose. This is sugar in the blood. A healthy liver helps the body keep a normal glucose level. If a blood test reveals that glucose is low, this may mean the liver is not working correctly.
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Coagulation studies (PT & INR) These test the ability of the blood to clot. The liver makes a protein that helps with clotting. Problems with clotting can be a sign of liver disease.
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Serum bile acid (SBA). This is the amount of bile acids in the blood. A high level may mean that bile ducts are blocked.
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Vitamins A, D, E, and K. These are fat-soluble vitamins that are absorbed by the liver, with help from bile. If a blood test shows that levels of these vitamins are low, this could mean your child’s liver is not absorbing them correctly.
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Zinc. This is a nutrient that is absorbed by the liver. If a blood test shows that your child’s zinc level is low, this could mean the liver isn’t absorbing zinc correctly.