The ALT AST blood test combination is often ordered to gain a glimpse into a patient’s liver health. Not only are they considered to be the two most important tests to discover the presence of a liver injury, but they can also be used to determine certain organ disorders.
These two blood tests are often used in conjunction with the ALP blood test, with results compared, to determine the total extent of liver health.
When to Ask a Doctor About the ALT AST Blood Test Combination
These two blood tests are often ordered when a patient is reporting the signs and symptoms of a possible liver disorder. Common symptoms may include weakness, fatigue, a loss of appetite, nausea, vomiting, and swelling of the abdomen which may or may not be painful.
Liver-specific symptoms may also be present. This may include a yellowing of the skin, dark urine, light-colored stools, and frequent itching.
These blood tests may also be ordered on a regular basis for individuals who have an increased risk of suffering liver damage, but may not be experiencing any of the bothersome symptoms listed above. Examples of this include hepatitis viral exposure, a history of alcoholism or heavy drinking, a family history of liver disease, being obese, or having diabetes.
Certain medications can affect ALT and AST levels as well and may require ongoing monitoring to determine the health of the liver.
What Do My Test Results Mean?
The normal range for the ALT blood test is usually reported between 5-55 units per liter. The AST blood test has a normal range of 10-40 units per liter. Every laboratory has its own normal range, however, so certain results that fall outside of these reported norms may still be considered a “normal” result by some medical providers.
In general terms, the amount of elevation that is seen above this normal range is treated as an indication of the severity of infection or injury that is affecting the liver. This means a test result that is 20 times higher than the maximum normal result would indicate more severity in the injury to the organ than a test result which is just 5 times higher.
Elevated readings from these blood tests are often the result of an acute viral hepatitis infection. This includes Hepatitis A and B. Chronic viral hepatitis can also produce elevated results. Liver cirrhosis also elevates ALT and AST levels, as does organ damage from alcohol, or a diminished flow of blood from the heart to the liver for some reason.
Lower than normal test results for ALT and AST are generally treated as a “normal” result. A healthy liver produces very little ALT and AST. There may be co-related conditions which are affecting the blood test results which need to be examined to determine the lower-than-normal results experienced.
Here’s What You Need to Know
Certain low-level rises in ALT and AST can also be seen with certain lifestyle choices, including strenuous workouts, shots, or injections. Anything that strains the muscles may increase ALT levels. AST levels naturally rise after a surgery, receiving an acute burn, or during a pregnancy. Individuals with frequent seizures will typically have higher than normal AST levels present on a regular basis.
Prescription drugs aren’t the only cause of rising ALT and AST levels either. Some natural health products have also been known to influence blood test results. Patients taking vitamins and herbal supplements will wish to tell their healthcare provider about everything they are taking on a regular basis.
And although this blood test combination is generally associated with liver health, there are other conditions that may cause elevations of ALT and AST. Anything that affects the heart or skeletal muscles will also elevate test results above normal ranges. Some increases are also seen with acute health issues associated with the pancreas.
Depending on what is suspected to cause the liver damage, follow-up tests may be required after this panel. This may include testing for copper, ethanol, iron, drug abuse, and hepatitis infection. Certain medications may be altered to determine if they are causing side effects which could be damaging the liver.
The ALT AST blood test combination is used to determine the extent of liver damage and overall health. Only a medical provider can determine what a test result means for each individual. Use this guide to discuss your current health concerns during your next appointment to determine if these blood tests may be right for you.