Long-term drinkers are prone to facial darkness, for the following reasons: 1. The main reason is that the acetaldehyde in alcohol has caused serious damage to the liver, so that the metabolic function of the liver is seriously affected. 2. The liver inactivates a part of the enzymes involved in pigment metabolism, which can cause pigmentation, and facial darkness can occur, mostly in patients with alcoholic cirrhosis caused by long-term drinking, such facial darkness It is also known as hepatopathy. In pigment metabolism, the most common enzyme is tyrosinase, which needs to be metabolized in the liver, and the inactivation of tyrosinase is impaired by cirrhosis, which increases the amount of this enzyme in the blood. Tyrosinase can promote an increase in melanin, which can make the skin look dark and gray.