In a person, addict for alcohol a part of alcohol is changed to acetaldehyde. Hangover is due to it. Acetaldehyde stimulates formation of fat which is deposited over the wall of arteries and in the cells of liver . With the accumulation of fat the liver cell fail to produce protein and enzymes. There is little regulation of fat, protein and carbohydrate metabolism. This disorder is called fatty liver syndrome. Liver later turns into a fibrous organ.