After the liver is damaged, the body sends out obvious signals in many ways, such as gastrointestinal discomfort, skin abnormalities, abdominal pain, etc. 1. Gastrointestinal discomfort: patients may have symptoms such as loss of appetite, aversion to oil and grease, indigestion, etc., and may have manifestations such as bitter taste in the mouth, bad breath, sour taste in the mouth, nausea, etc., and in severe cases, black stools may appear. 2. Skin abnormalities: facial skin is dark, black and without brightness; spider nevi may appear on the neck as well as the chest and back, especially on the front chest where small blood vessels are obviously distributed. Some patients have yellowish and itchy skin due to bilirubin gathering in the blood as a result of impaired excretion of bilirubin due to affected liver function. 3. Abdominal pain: the pain is not obvious, mainly manifested as localized hidden pain or dull pain, which usually occurs in the right upper abdomen.