Fatty liver does not usually lead to spider nevi, but when it progresses to the stage of cirrhosis it may lead to the formation of spider nevi, the appearance of spider nevi may also be related to other diseases that lead to increased estrogen. Fatty liver is mainly associated with liver cell damage and increased fat in the liver cells due to heavy alcohol consumption, obesity, diabetes, and heavy drug use. The onset of fatty liver is insidious and progresses slowly, and there is usually no obvious clinical manifestations in the early stage. In moderate to severe cases, there may be weakness, epigastric pain and discomfort, loss of appetite, bloating, anorexia, nausea and vomiting, and constipation. If fatty liver is not intervened in time, it may lead to severe hepatitis, cirrhosis, liver failure and other serious complications. At this point, the normal physiological function of the liver will be affected, which will lead to insufficient inactivation of estrogen in the liver, resulting in increased levels of estrogen in the body, which will lead to the appearance of spider nevi. In addition to liver diseases, spider nevi may also be associated with rheumatism, rheumatoid arthritis, Cushing’s syndrome, vitamin B deficiency, pigmented dry dermatosis, or oral estrogen, prolonged use of medications that cause liver damage, and women who are in the period of pregnancy. If spider nevus changes appear on the skin, it is recommended that the cause be clarified after timely consultation and appropriate treatment be carried out.