How To Diagnose Fatty Liver And Alcoholic Liver Disease

Fatty liver disease can be categorized into two main types: non-alcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease (AFLD). Each has distinct diagnostic criteria that healthcare professionals use to identify the condition accurately.

Diagnosing Non-Alcoholic Fatty Liver Disease

The first step in diagnosing NAFLD involves evaluating a patient's alcohol consumption history. A diagnosis may be considered if there is little to no alcohol intake — specifically, less than 140 grams per week for men and less than 70 grams per week for women.

Next, imaging tests such as ultrasound or CT scans are used to detect fat accumulation in the liver. In some cases, a liver biopsy may be necessary to confirm the presence of fatty liver disease at a cellular level. It is also crucial to rule out other potential causes of liver fat buildup, such as viral hepatitis, drug-induced liver injury, autoimmune liver diseases, Wilson's disease, or hypothyroidism. Once these conditions are excluded, a diagnosis of NAFLD can be made.

Identifying Alcoholic Fatty Liver Disease

For alcoholic fatty liver disease, the diagnostic process begins with a detailed history of alcohol use. A key indicator is a history of excessive alcohol consumption — typically more than five years of daily intake, with men consuming over 40 grams of alcohol per day and women over 20 grams. In some cases, AFLD can also develop after a shorter but more intense period of alcohol use, such as heavy drinking exceeding 80 grams of alcohol per day for two consecutive weeks.

Blood tests play a significant role in confirming the diagnosis. Elevated levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), with an AST/ALT ratio greater than 1.5, are commonly observed. Additionally, increased gamma-glutamyl transferase (GGT) and mean corpuscular volume (MCV) levels support the diagnosis.

Finally, imaging studies like ultrasound or CT scans are used to assess the liver's condition. If these tests show signs consistent with fatty liver and other causes have been ruled out, alcoholic fatty liver disease can be confidently diagnosed.