Understanding Lab Test Results

Editors Note: If you have concerns or questions about your test results, always ask a medical professional.

Lab tests (also called blood work) are common when living with the hepatitis C virus (HCV). In some cases, lab tests are used to monitor treatment side effects.

Other times, they are used to measure how well the body is functioning. They can be used to look for specific signs of damage, too^1-4.

Although lab tests are common, their results can be confusing. Plus, the “normal” range for lab tests can vary.

The specific range that your doctor, hospital, or lab considers normal will be listed on your lab results¹.

Below are several common types of lab tests and what they look for.

Liver function testing

Liver function tests (LFTs) measure liver-related proteins. When these proteins are abnormal, it can mean the liver is not working well or is damaged. Several specific LFTs include^1,4:

• Alanine aminotransferase (ALT) – High ALT levels may indicate liver inflammation or damage.
• Aspartate aminotransferase (AST) – AST can be high when other parts of the body, like muscles, are damaged.
• Bilirubin – A waste product from the breakdown of red blood cells. When the liver is working well, it gets rid of bilirubin. When bilirubin is high, there may be a problem with the liver or gallbladder.
• Albumin – The liver makes albumin to help with water balance and other functions. When albumin is low, it may mean the liver is not working as well as it should.
• Prothrombin time (PT) – The liver also makes prothrombin, which is involved in blood clotting. Not enough prothrombin can lead to severe bleeding. PT measures how long it takes for a person’s blood to clot.
• Alkaline phosphatase (ALP)– Found in the liver, bile ducts (from the gallbladder), and bones. It can be elevated when a person has liver or gallbladder disease or in conditions affecting the bones.
• Gamma-glutamyl transpeptidase (GGT) – Found in the liver and bile duct system. When high, it can signal a problem in these areas.

Complete blood count

A complete blood count (CBC) looks at things related to the blood and the cells within it. Things a CBC measures include^2,5:

• White blood cells (WBCs) – Cells that fight infections and germs. High WBCs may mean a person has an infection or inflammation. In some cases, specific types of WBCs may be listed on a lab report, such as neutrophils and lymphocytes. When 1 type of cell is high, it may point toward a specific infection. For example, lymphocytes may be high in a viral infection.
• Red blood cells (RBCs) – Cells that carry oxygen through the body and move carbon dioxide to the lungs where it is exhaled. Low RBCs may mean a person has anemia.
• Hemoglobin (HGB) and hematocrit (HCT) – HGB is a protein that carries oxygen within red blood cells. HCT is the percentage of red blood cells in the total amount (volume) of a person’s blood. If these are low, it may mean a person has anemia.
• Platelets – Platelets, also called thrombocytes, help the blood clot. When platelets are low, a person may be at risk for severe bleeding.

In some cases, a sample of your blood will be looked at under a microscope. This is called a blood smear.

It allows doctors to look at your blood cells to see if there is anything abnormal about their size, shape, or color.

Chemistry panels

Chemistry panels cover a variety of tests, including³:

• Electrolytes – This measures the number of specific electrolytes in the blood. Examples include calcium, sodium, or potassium.
• Glucose – Glucose is another word for sugar. Low blood sugar is called hypoglycemia. High blood sugar is called hyperglycemia. Each can have different effects on the body.
• Kidney function – Some chemistry panels look for markers of good kidney function. These tests look for levels of creatinine or blood urea nitrogen (BUN) in the blood. Both relate to how well the kidneys are working. If a person’s kidneys are damaged, creatinine and BUN may be high.

This is not a complete list of all potential blood tests you might have. Also, different drugs can impact many of these tests.

Tell your doctor about all drugs and supplements you are taking before a blood test^1-3,6.

If you have any specific concerns about your blood test results, talk with your doctor. They can help figure out what the numbers mean for your specific case.

Written by: Casey Hribar | Last reviewed: February 2022