What is a liver function test?
May 20, 2022
A liver function test is a test that checks the levels of certain enzymes and proteins in your blood. Some tests look for enzymes that may only be present in your blood when your liver is damaged or diseased. Others inspect the organ to ensure it is functioning as it should. Your liver is responsible for a wide range of essential activities.
Food is broken down into the digestive system, and this process helps provide nutrients and clean the blood. Proteins are made from amino acids, and this process helps provide energy and store fat. If something goes wrong with it, you may experience yellow skin, slurred speech, and problems with movement. That’s when you might need a liver test.
Why is a liver function done?
Liver function tests are done to check whether the liver is functioning correctly. You may have this test to check for liver disease such as hepatitis. If you have taken the test and it shows that you have the disease, you will need to go to the doctor to seek treatment immediately. Common symptoms of liver problems include:
- Loss of appetite
- Nausea or vomiting
- Weakness or feeling very tired
- Yellowing of the eyes or skin (jaundice)
- Dark urine or light poop (less common)
- Swelling of the abdomen (less common)
If you are at risk for liver damage or disease, your doctor may order a liver test.
- Drinking a lot of alcohol or having an alcohol use disorder
- Have a family member with liver disease
- Very overweight, especially if you also have diabetes or high blood pressure
- Taking medicines that can damage the liver
- Have gallbladder disease or anaemia
A liver test can also help your doctor see if your disease worsens or how well your treatment is working.
Types of Liver Tests
Different liver function tests can be used to determine the liver’s health. Some of these tests include liver enzymes, bilirubin levels, and liver function tests for specific types of proteins. Liver function tests measure particular enzymes and proteins in your blood. If you have atypical results on any of your liver tests, it’s usually best to have a follow-up to find out the cause of the atypical results. Even mild elevations in test results can be associated with liver disease. Common liver function tests include checking the levels of certain chemicals in the blood.
Common liver function tests include:
1. Alanine transaminase (ALT) test
The Alanine Transaminase (ALT) test is used by your body to break down protein. If the liver is damaged or not functioning correctly, ALT can enter the bloodstream. The increase in ALT levels is due to this. A higher than the typical result for this test may signify liver damage. It is estimated that about 10% of people in the United States have elevated ALT levels.
2. Alkaline phosphatase (ALP) test
The ALP test is used to determine the level of ALP in a person’s blood. ALP is an enzyme found in your liver, bile ducts, and bone. If you have liver damage or disease, a blocked bile duct, or bone disease, your levels of liver enzymes might be high.
3. The Albumin Test
The albumin test is a test to check your liver’s protein production. The albumin test measures how well your liver is producing this protein.
4. Bilirubin Test
The bilirubin test measures the level of bilirubin in the blood.Bilirubin is a by-product of the process of breaking down red blood cells. The liver processes typically it. The drug passes through the liver before being excreted through your stool. A damaged liver can’t properly process bilirubin, leading to a yellowing of the skin and eyes. This can lead to an unusually high level of bilirubin in the blood. In addition, some inherited diseases can cause bilirubin levels to rise even when the liver is working normally.
5. Aspartate transaminase (AST) test
AST is an enzyme found in your liver. High blood levels could be an indication of damage or disease.
6. Gamma-glutamyltransferase (GGT) test
High levels of the GGT enzyme may indicate liver or bile duct damage.
7. L-lactate dehydrogenase (LD) test
LD is another high enzyme when you have liver damage, but other conditions can also raise its level.
8. The prothrombin time (PT)
PT test is a blood test that measures the time it takes for blood to clot. This test measures how quickly your blood clots. If it lasts long, it could be a sign of liver damage.
Symptoms of Liver Disorder
The symptoms of a liver disorder can vary, but they can often include fatigue, nausea, and anaemia. Problems with the liver can make a person very ill and even life-threatening. Symptoms of liver disease include:
- Tiredness or loss of energy
- Weight loss
- Jaundice (yellow skin and eyes)
- Fluid buildup in the abdomen is known as ascites
- Discoloured discharge (dark urine or light-coloured stools)
- Stomach pain
- Atypical bruising or bleeding
Your doctor may order a liver function test if you have symptoms of liver disease. Liver function tests can help monitor the progression or treatment of an illness and test for certain medications’ side effects.
How should one get prepared for a liver function test?
Your doctor will give you specific instructions on preparing for the blood sample portion of the test. Some medications and foods can affect the enzymes and proteins in your blood. Your doctor may ask you to avoid some types of drugs, or they may ask you to avoid eating anything for a certain period before the test. Be sure to keep drinking water before the test. If you plan to have your blood drawn by a medical expert, you might consider wearing a shirt with sleeves that can easily be rolled up. This will make it easier for the expert to collect the sample.
What are the potential risks of the liver test?
Blood draws are standard procedures and rarely cause any serious side effects. However, the risks of giving a blood sample can include:
- Bleeding under the skin or hematoma
- Excessive bleeding
What are a few steps post the liver test?
After the test, you can usually resume your daily activities. If you feel faint or lightheaded when you have your blood drawn, you should rest before leaving the testing facility. These tests may not determine your exact condition or the severity of liver damage, but they may help your doctor determine the next steps. The doctor will call you to let you know your test results or schedule a follow-up appointment to discuss them. If your liver function tests are abnormal, your doctor will look at your medications and medical history to find the cause. For example, if you drink alcohol frequently, you need to stop drinking it. If your doctor finds that a medicine is causing elevated liver enzymes, they will advise you to stop taking the medication.
People also ask
1. What are the five functions of the liver?
Five significant functions of the liver are
- Metabolism and Detoxification.
- Protein synthesis.
- Storage of vitamins and minerals.
2. What are the seven main functions of the liver?
Seven primary functions of the liver include
- Bile production and excretion
- Excretion of bilirubin, cholesterol, hormones, and drugs
- Metabolism of fats, proteins, and carbohydrates
- Enzyme activation
- Storage of glycogen, vitamins, and minerals
- Synthesis of plasma proteins, such as albumin, and clotting factors
- Blood detoxification and purification
3. What are the symptoms of poor liver function?
- Skin and eyes that appear yellowish (jaundice)
- Abdominal pain and swelling.
- Swelling in the legs and ankles.
- Itchy skin.
- Dark urine colour.
- Pale stool colour.
- Chronic fatigue.
- Nausea or vomiting.
4. What causes poor liver function?
Many diseases and conditions can lead to liver failure, including hepatitis B and C, non-alcoholic fatty liver disease, alcohol abuse, and hemochromatosis. Chronic liver failure often results from cirrhosis.