ALT (Alanine transaminase) is an enzyme found primarily in the liver. Healthcare professionals usually use an ALT blood test to assess liver health. This blood test is often part of a comprehensive liver and metabolism panel. High ALT blood levels may suggest that you have liver damage and/or liver disease.
What is ALT (alanine transaminase)?
Equally called alanine aminotransferase, Alanine transaminase (ALT) is an enzyme found primarily in the liver, but it is also found in other body parts.
Enzymes are cellular proteins in that act as catalysts, allowing certain bodily processes to occur. There are thousands of body enzymes having very important functions in your body.
What is the alanine aminotransferase ALT test?
A blood test that checks for liver damage is known as an alanine aminotransferase (ALT) test. With this test, your health care provider can determine if an injury, medication, or disease has caused harm to your liver.
Important functions of the liver include:
- A fluid called bile is produced, which helps the body in food digestion.
- Produces cholesterol and protein.
- It removes toxins and other waste products from the blood.
Diseases such as cirrhosis and hepatitis can cause liver damage and prevent your liver from doing many of its functions.
ALT blood test can equally be called:
- SGPT.
- Serum glutamate pyruvate transaminase.
- GPT.
- ALT (Alanine transaminase).
- Alanine aminotransferase.
What is the purpose of ALT blood test?
Assessing the health of your liver constitute the purpose of the ALT blood test. An ALT blood tests can help identify liver problems since cell damage in your liver can cause ALT to leak into your bloodstream.
Enzymes and other liver compounds are usually analyzed in the blood along with ALT. in total, these different test measurements can be used for monitoring, detection, and diagnosis.
Diagnosis: It is a test that is done after symptoms appear. The goal in diagnosis is to find the cause or problem relating to the symptom. The ALT blood test can help diagnose liver disorder symptoms such as vomiting and itching, stomach pain, nausea, jaundice, loss of appetite, and fatigue.
Screening: Before symptoms appear, screening tries to detect the health problems. In some liver diseases, ALT blood levels can rise before appearance of symptoms. Therefore, ALT blood test and other liver enzymes can be done for early diagnosis. This is generally recommended if you have liver disease risk factors such as: a family history of liver problems, obesity, diabetes, or Excessive alcohol use. Request an ALT blood test during a routine health checkup even if you don't have any risk factors.
Monitoring: It describes all the methods that can be used to follow the course of your disease. Ongoing tests may be done to see how your levels change over time, if you have an abnormal ALT blood test or liver disease. Side effects of medications that affect the function and health of the liver can also be monitored with ALT blood tests and liver enzyme.
Do I need an ALT blood test?
As part of a routine checkup, your doctor may order an ALT blood test. Checks of how well your liver is working is usually done at the same time as ALT test and other liver function tests. If you have symptoms of liver damage, these test may also be ordered, live damage signs include:
- Swollen ankles and feet
- Light-colored stools and/or Dark urine
- Constant itches
- Vomiting and nausea
- A condition that causes the eyes and skin to turn yellow (Jaundice)
- Pain and/or swelling in the belly (abdomen)
- Loss of appetite
- Fatigue
- Weakness
If you are at high risk of liver damage, your doctor may also order an ALT blood test. These damages can be due to:
- High blood sugar (Diabetes)
- Consuming medicines that can result to liver damage
- Contact with hepatitis or Hepatitis
- Family liver disease history.
- AUD (Alcohol abuse disorder).
- Obesity.
How is aspartate transferase (AST) different from alanine transferase (ALT)?
AST (Aspartate transferase) is another enzyme that is often measured along with comprehensive metabolic panels or AST in liver function panels. When certain body cells are damaged, both enzymes can enter the bloodstream.
Larger amounts of AST are found in other body parts, such as the pancreas, skeletal muscle, and heart even though ALT and AST are generally considered to be liver enzymes. For this reason, ALT is believed to be more directly related to the health of your liver. However, health professionals use both enzyme measures to assess your liver health.
What happens during an ALT blood test?
During a blood draw or blood test, you can expect the following experiences:
Your doctor examines your arm for easily accessible veins while you’re seated in a chair. This is usually on the other side of the elbow, on the inside of the arm.
They clean and disinfect the area once the vein is found.
To take a blood sample, they insert a small needle into your vein. It may feel like a small pinch.
A small amount of blood will collect in the tube after the needle is inserted.
They remove the needle once there is enough blood to test, and place a cotton gauze or ball over the area to stop bleeding.
You’re done once they put a bandage on that spot.
It usually takes less than five minutes to complete the whole procedure.
What are ALT blood test risks?
An ALT blood test is generally safe. Minor risks may usually include:
- Slight pain upon inserting the needle.
- Bruises
- Infection
- Feeling dizzy or fainting
- Bleeding
ALT blood Test Results
Receiving ALT blood test results
Your doctor's office can notify you of the test results. ALT blood test results are usually available within a few business days. You can also usually receive a copy of the ALT blood test results electronically or by mail.
Access to home ALT blood test results is usually electronically through a dedicated website or a smartphone app. Because it takes time for the sample to reach the lab by mail, it may take a few more days to receive results.
Normal range for ALT blood test
From laboratory to laboratory, the normal range for ALT (alanine transaminase) varies. 7 to 56 U/L (units per liter) is the common reference range for an ALT blood test. Generally, ALT blood values are lesser in individuals assigned female at birth than in individuals assigned male at birth.
It is essential to review the ALT blood test result report to determine the laboratory-specific reference range. Given that the ranges can vary by laboratory.
Interpreting ALT blood test results
The test report must include the reference range used by the laboratory to classify ALT blood levels as normal or abnormal and a line showing the ALT blood level. ALT is measured in most cases in international units per liter (IU/L) or units per liter (U/L).
Remember that there is no universal reference range for ALT when reviewing the results. What is considered as normal ALT range may be subject to variations through some laboratory methods that affect ALT blood test results. It is for this reason essential to look at the range provided by the special laboratory that tests your blood ALT.
Most commonly, other liver enzymes and proteins along with ALT are analyzed in a panel test. The laboratory's reference range for each test measurement and your values will be shown on your ALT blood test report. This is therefore very important since your ALT blood test results will be interpreted by viewing together all these test components.
High ALT blood levels can be caused by injury or damage to cells. An abnormal ALT blood test result is commonly associated with liver diseases since ALT is most concentrated in the liver, such diseases include: scarring (cirrhosis) and Inflammation (hepatitis).
Several factors can influence ALT; elevated ALT in most cases is not a sign of severe liver disease. Therefore ALT can be increased without any health problems.
Your doctor will consider several factors in order to interpret the ALT blood test results. This includes other reading scores from your exams and medical history, as well as your current health. Your doctor may additionally consider individual factors that may affect your normal ALT level, such as:
- Menstruation: ALT levels rise and fall during the menstrual cycle.
- Age: although the exact reasons are unknown, ALT levels tend to decrease with age.
- Body Mass Index: A relationship between Body Mass Index and ALT blood levels that could change the way test results are interpreted in people with obesity have been found in several research studies.
- Exercise: Extreme or intense exercise can result to a temporary increase in ALT blood levels.
- Medications: Some medicines and dietary supplements can change ALT test measurements.
- Gender: Due to hormonal differences, men tend to have higher ALT levels.
High ALT blood levels can be as a result of a liver condition. A moderate or mild increase, most especially if it continues through multiple tests, may be due to a chronic condition. However, the degree of liver damage cannot be determined only by the degree of elevation alone.
ALT blood tests alone cannot identify an underlying cause since many types of liver conditions can cause elevated ALT blood levels. ALT can rise due to disease outside of the liver although it is rare. Seeing how other liver enzymes relate to ALT blood levels can provide clues that can help your doctor recommend appropriate follow-up tests and assess your situation.
What your results mean for your overall health and the factors that influence the interpretation of your ALT blood test can be better explained by your doctor.
What else should I know about ALT blood test?
Raises in ALT blood levels as they are released from the muscles into the bloodstream can be due to strenuous exercise or Injection of drugs into muscle tissue.
High ALT blood levels that result to liver damage can also be caused by certain medications. This is true of some "natural" health products and prescription drugs and occurs in a minority of patients. Discuss all medications and health products you are taking with your doctor if he determines that you have high ALT blood levels.
When to call a doctor?
Don't be afraid to ask your doctor if you have questions about your alanine transaminase ALT blood test results.
- If you have liver damage symptoms, including stomach pain or jaundice.
- If you have new or concerning symptoms or been diagnosed with liver disease.
Message from Big Man Lab
It can be stressful seeing abnormal test results. Keep in mind that high levels of ALT (alanine transaminase) do not always mean that you need treatment and have a liver disease. One in 20 healthy people will have results outside the ALT blood normal range since several factors can affect the ALT blood level. To determine the root cause of the abnormal reading, your doctor will let you know if further testing is needed. The health care provider is there to help you so don't be afraid to ask your questions.
