Non-alcoholic fatty liver disease (NAFLD) is a condition in which fat builds up in the liver, causing inflammation and damage. It is the most common form of liver disease in the United States, affecting up to 25% of the population. NAFLD is closely linked to obesity, diabetes, and high cholesterol, and can lead to serious complications such as cirrhosis and liver cancer. Treatment typically involves lifestyle changes such as weight loss, exercise, and a healthy diet.