Know Your Liver Numbers

Your liver plays a vital role in keeping your body healthy by processing nutrients, filtering toxins, and aiding digestion. Because the liver is essential to many bodily functions, it’s important to monitor its health, especially if you have risk factors like alcohol use, obesity, or a family history of liver disease. One of the most common ways to assess liver health is through liver function tests (LFTs), also known as liver blood tests.

These tests measure certain enzymes and proteins in your blood to see how well your liver is working. In this blog, we’ll explore what these tests are, what your liver numbers mean, and when you should pay attention to them.

What Are Liver Function Tests (LFTs)?

Liver function tests are a group of blood tests that give a snapshot of your liver’s health. These tests measure the levels of various enzymes and proteins that are produced or processed by the liver. The results help doctors assess how well your liver is functioning and can detect liver damage, inflammation, or diseases such as hepatitis or fatty liver.

Here are some key liver numbers to know:

1. Alanine Aminotransferase (ALT)

Normal range: 7 to 56 units per liter (U/L)
ALT is an enzyme found mainly in the liver. When liver cells are damaged, they release ALT into the bloodstream. High levels of ALT can indicate liver inflammation or injury, which may be caused by conditions like hepatitis, fatty liver disease, or excessive alcohol consumption.

2. Aspartate Aminotransferase (AST)

Normal range: 10 to 40 units per liter (U/L)
AST is another enzyme that, like ALT, is released into the bloodstream when the liver is damaged. While AST is found in the liver, it is also present in the heart and muscles. Elevated AST levels could indicate liver disease, but they may also be linked to muscle injuries or heart problems, so it’s important to consider AST levels alongside other liver tests.

3. Alkaline Phosphatase (ALP)

Normal range: 44 to 147 units per liter (U/L)
ALP is an enzyme found in the liver, bile ducts, and bones. High levels of ALP may indicate bile duct obstruction, liver inflammation, or bone diseases. In children and pregnant women, higher ALP levels are normal due to bone growth and changes in the body during pregnancy.

4. Gamma-Glutamyl Transferase (GGT)

Normal range: 9 to 48 units per liter (U/L)
GGT is another enzyme that helps transport amino acids in the body. High GGT levels can be a sign of liver disease, particularly related to alcohol use, bile duct issues, or fatty liver. Elevated GGT is often used to confirm whether elevated ALP levels are related to liver disease.

5. Bilirubin

Normal range: 0.1 to 1.2 milligrams per deciliter (mg/dL)
Bilirubin is a yellow pigment produced during the breakdown of red blood cells. The liver processes bilirubin so that it can be excreted in stool. Elevated bilirubin levels can cause jaundice, a yellowing of the skin and eyes, and may indicate liver disease, bile duct obstruction, or hemolysis (the breakdown of red blood cells).

6. Albumin and Total Protein

Normal range for Albumin: 3.5 to 5.0 grams per deciliter (g/dL)
Normal range for Total Protein: 6.3 to 7.9 grams per deciliter (g/dL)
Albumin is a protein made by the liver, and it helps keep fluid in your bloodstream from leaking into other tissues. Total protein measures the overall amount of protein in your blood, including albumin and other proteins. Low levels of albumin and total protein can indicate liver damage, malnutrition, or kidney disease.

7. Prothrombin Time (PT)

Normal range: 9.5 to 13.8 seconds
PT measures how long it takes for your blood to clot. Since the liver produces proteins that are involved in clotting, a prolonged PT can be a sign of liver dysfunction or damage. Liver diseases like cirrhosis can result in slower clotting times.

What Do Your Liver Numbers Mean?

Understanding your liver numbers can help you and your doctor determine whether your liver is functioning properly or if there are signs of liver damage or disease. Here’s what different results might indicate:

Normal liver numbers generally mean your liver is functioning well, and there’s no sign of damage or inflammation.
Elevated ALT or AST levels usually suggest liver cell damage, which may be caused by hepatitis, fatty liver, or alcohol use.
High ALP levels could point to a blockage in the bile ducts or bone disorders.
Increased bilirubin levels may cause jaundice and indicate liver disease or bile duct problems.
Low albumin or total protein levels can be a sign that your liver is not making enough proteins due to liver disease or malnutrition.
Prolonged PT may signal a problem with your liver’s ability to produce clotting factors, suggesting liver damage or cirrhosis.

When Should You Be Concerned?

Mildly elevated liver enzyme levels are often not a cause for concern, and they may return to normal on their own. However, persistently high or very elevated levels of liver enzymes can be a sign of a more serious condition and may require further testing or treatment.

You should see a doctor if you experience any of the following symptoms:

Yellowing of the skin or eyes (jaundice)
Unexplained weight loss
Fatigue or weakness
Abdominal pain, especially in the upper right side
Dark urine or pale stools
Nausea or vomiting

How to Keep Your Liver Healthy

To maintain healthy liver numbers and support your liver’s health, consider the following lifestyle tips:

Limit alcohol consumption: Excessive drinking can damage your liver cells over time, leading to conditions like fatty liver disease or cirrhosis.
Maintain a healthy weight: Obesity increases the risk of fatty liver disease, which can lead to liver damage.
Eat a balanced diet: A diet rich in fruits, vegetables, lean proteins, and whole grains can support liver health.
Exercise regularly: Physical activity helps you maintain a healthy weight and reduces the risk of liver disease.
Avoid risky behaviors: Sharing needles or engaging in unprotected sex can increase the risk of contracting hepatitis, which can harm the liver.

Conclusion

Liver function tests provide important information about the health of your liver. By understanding your liver numbers, you can take proactive steps to protect your liver and seek medical care when needed. Keeping an eye on your liver health is essential, especially if you have risk factors like alcohol use, obesity, or a family history of liver disease.

Taking care of your liver means taking care of your overall health. If your liver numbers are outside the normal range, talk to your doctor to understand the cause and take the necessary steps to keep your liver functioning well.