Liver function tests (LFTs) are blood tests that provide insights into liver health, helping healthcare providers identify problems and monitor treatment. With growing interest in at-home health testing, this article explores the accuracy and utility of home liver function tests.
Understanding Liver Function Markers
Standard liver function tests measure substances in the blood, each providing specific information. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are enzymes found in liver cells. Elevated levels suggest liver cell damage, as these enzymes leak out when cells are injured.
Alkaline phosphatase (ALP) is associated with bile ducts and bone health; elevated ALP can indicate issues with bile flow or bone conditions. Bilirubin, a waste product from red blood cell breakdown, is processed by the liver; high levels can signal problems with bile production or excretion, leading to jaundice. Albumin, a protein produced by the liver, helps regulate fluid balance; low levels may indicate impaired liver function.
Home Testing Options for Liver Health
Several “home” tests are marketed for liver health, varying in scope and methodology. Many involve collecting a finger-prick blood sample sent to a laboratory for analysis. Common markers measured include ALT, AST, and total bilirubin.
Some companies offer tests measuring ALT, AST, and total bilirubin from a dried blood sample. Other services provide panels including albumin, ALT, alkaline phosphatase, AST, and total protein, though these often require visiting a partnered lab for blood collection. Urine tests are also available, but offer less comprehensive information than blood tests.
Assessing the Reliability of Home Tests
Home liver function tests are generally not as accurate or reliable as professional laboratory tests. Most home tests do not measure the full range of markers in a comprehensive lab LFT panel, which includes ALT, AST, ALP, bilirubin, albumin, and gamma-glutamyl transferase (GGT). This provides only a partial view of liver health.
Accuracy and precision can be compromised in home testing due to user error during sample collection, issues with sample integrity during transport, and less sensitive detection methods. Interpreting results requires medical expertise, as abnormal levels do not always indicate severe dysfunction and can vary daily. While some tests are processed by Clinical Laboratory Improvement Amendments (CLIA)-certified labs, not all home tests are well-regulated or FDA-approved for diagnostic purposes.
When to Seek Professional Liver Evaluation
Home liver tests are not a substitute for professional medical evaluation. Individuals should consult a healthcare professional if they experience symptoms such as persistent fatigue, unexplained weight loss, loss of appetite, yellowing of the skin or eyes (jaundice), dark urine, light-colored stools, itchy skin, or upper abdominal pain. These symptoms can indicate underlying liver issues that require prompt medical attention.
Certain risk factors also warrant professional liver evaluation, including ongoing alcohol use, obesity, type 2 diabetes, a history of viral hepatitis (B or C), exposure to toxins, and a family history of liver disease. A doctor can assess symptoms, consider risk factors, and order comprehensive tests to diagnose and monitor liver conditions. Relying solely on home test results can delay proper diagnosis and treatment, potentially leading to advanced liver damage.