This article provides a literature review on non-alcoholic fatty liver disease (NAFLD), a polyetiological condition. Excessive consumption of foods rich in animal fats and easily digestible carbohydrates leads to an influx of free fatty acids (FFAs) from the gastrointestinal tract into the bloodstream, ultimately accumulating in the liver, resulting in steatosis. Inflammatory mediators actively secreted by adipose tissue directly damage hepatocyte membranes, leading to fibrotic tissue accumulation in the liver. The key feature of NAFLD is its asymptomatic course, with diagnosis often occurring incidentally through laboratory and imaging studies in patients with metabolic syndrome. As a widespread pathology, NAFLD requires thorough investigation into its pathogenesis and the development of optimal non-invasive diagnostic methods to detect and assess its advanced forms (steatohepatitis, fibrosis, cirrhosis).