The GPT blood test is used to help determine the levels of ALT that are present in the bloodstream. ALT is typically present in higher levels when a liver injury has occurred. It is also higher in individuals who have liver disease. Sometimes ordered with the AST blood test, the GPT blood test helps to determine if a disease is present, if treatments are working, or if trauma has happened to the liver for some reason.
When Is the GPT Blood Test Ordered?
A medical provider will typically order a liver panel or the GPT blood test independently if someone is displaying the signs and symptoms of potential organ damage or malfunction. This usually involves some form of unusual fatigue or weakness, but may also include a loss of appetite, frequent nausea that may lead to vomiting, and abdominal pain.
There may also be swelling in the limbs, dark urine that looks almost brown in color, and gray colored bowel movements. In severe cases, there may also be a yellowing of the skin and eyes and generalized itchiness of the skin.
Sometimes a medical provider may order the GPT blood test if there are lifestyle habits that could be leading to liver damage, but not outward signs or symptoms have developed. This includes people who have a history of heavy alcohol abuse and those with a family history of liver disease. A possible exposure to hepatitis may also trigger this test being ordered and individuals who take medications that can damage the liver may have it ordered regularly to determine overall health status.
What Do My Test Results Mean?
Most of the time, the levels of ALT that can be detected by the GPT blood test are relatively low. Having results that are close to 0 is not unusual and common in people who have a healthy liver. Depending on the levels of abnormality, however, a medical provider may be able to interpret the results of this blood test to arrive at a potential diagnosis.
A positive test that is around 10x more than what would be considered normal is generally indicative of an acute viral infection of the liver. Most of the time this indicates the presence of hepatitis, but a severe viral infection of any sort may cause a similar result. When this happens, it may take 30-60 days for ALT levels to begin returning to normal. Multiple tests over this period of time may be ordered to track healing.
When results are very high, described as being at least 100x above what would be considered normal, then this is generally considered evidence that drug-induced liver damage has occurred. If there has been exposure to chemicals or a traumatic injury to the liver, these results may also be discovered. Sometimes this type of result is also evidence of a reduced blood flow to the liver.
Small heart attacks can also sometimes be detected through the GPT blood test with other testing methods fail. This is because the damage to the heart muscle tissue releases ALT that the test can detect.
Here’s What You Need to Know
ALT levels are very flexible and the GPT blood test is extremely sensitive. That means certain actions or activities can have a dramatic result on the test results. Something as simple as an injection, either from a vaccination or from routine medication, can cause ALT levels to rise. Anything that causes a muscle injury, in fact, can cause ALT levels to rise, including strenuous exercise from something as simple as lifting weights.
There are many drugs that can cause ALT levels to rise, but not to the extent that would be a reflection of a liver injury or damage. This includes supplements and other health products that do not require a prescription. For this reason, it is important to discuss with your doctor all of your medications and supplements so that the test results can be correctly interpreted.
Although you can directly increase your ALT levels through lifestyle habits, it is difficult to artificially lower ALT levels after they have risen. This test is only ordered when there is suspected liver damage, so it is not a blood test that everyone will receive. The GPT blood test results explained here will let you know what your results potentially mean, but specific results can only be interpreted by your medical provider. Discuss your medical history, take the key points from this guide, and discuss your results at your next appointment so an appropriate treatment plan can be developed if necessary.