What Is ALT? ALT is an enzyme found in many parts of the body, but the liver contains the highest concentration. This enzyme, formerly known by the name serum glutamic-pyruvic transaminase, or SGPT, is used by the body to break down food into energy. ALT levels normally remain fairly low, but rise when your liver is damaged. Because of this, a high ALT level are usually a straightforward indication that there is something wrong with your liver. How Does an ALT Test Work? Alanine transaminase, also known as ALT or SGPT, is an enzyme made by the liver to metabolize proteins. ALT is released into the bloodstream when liver cells are damaged. An ALT test measures the amount of ALT in the blood to assess if the liver is damaged. The most common reason to take an ALT test is to detect liver injury and to screen for/or help diagnose liver disease, as it is considered to be one of the best methods to identify liver issues. Why take an ALT Test? ALT blood tests are often part of liver function testing. The main reason to take an ALT test is if you or your doctor identify signs of liver damage or failure. It can also be taken to monitor the progression of liver diseases or to evaluate the effectiveness of treatment. Signs of Liver Damage or Failure Onset symptoms of liver failure include: NauseaLoss of appetiteFatigueDiarrheaAs you can see, the initial symptoms of liver failure are so broad that it can be difficult, if not impossible, to diagnose without testing. The following are symptoms of liver failure that indicate the disease has progressed to the point of requiring immediate treatment or hospitalization: Jaundice (yellow skin)Bleeding easilySwollen abdomen Hepatic encephalopathy (mental disorientation/confusion)SleepinessComaWhat can cause ALT levels to rise? There are many things may increase the ALT levels in the blood. Some of these include: Alcohol abuseHepatitis - an inflammatory condition of the liverCirrhosis - severe scarring and poor overall performance of the liver caused by high exposure to toxins like alcohol or viral infectionDeath of liver tissueA tumor in the liverPoor blood flow to the liverHemochromatosis - a disorder that causes iron build upMononucleosis - an infection usually caused by the Epstein-Barr virusPancreatitis - pancreas inflammationDiabetes Things to Know Beforehand You should tell your doctor about any drugs you are taking, as some prescription and over-the-counter medications can affect ALT levels. Acetaminophen (Tylenol) is a notable example. Your doctor may tell you to avoid taking some medications for a period of time prior to taking the test. Otherwise, there are not any precautions necessary to taking the test. How Is the Test Taken? Testing with Healthlabs.com is simple, quick, and easy. After you have purchased an ALT test and traveled to the lab you selected using our lab finder, a lab technician will perform a simple blood test. The technician inspects your arm for vein visibility first, chooses a spot to draw the blood, cleans the area with antiseptic, and wraps an elastic band around your upper arm in preparation for collection. The lab technician then carefully injects a sterile needle into the vein and draws blood. The entire process, depending on how busy the lab is, should take about 5-10 minutes. What your ALT Test Results mean The normal value of an ALT test depends on gender: ~29 to 33 U/L (units per liter) for men and ~19 to 25 U/L for women. ALT levels typically fall somewhere within the 7 to 55 U/L range. Certain factors like age and gender can affect this range, but doctors should be able to recognize abnormal values regardless. Both excessively high and low ALT levels are considered to be unhealthy, but higher-than-normal levels are the most likely to indicate liver damage.