Poor liver function may be caused by life factors, drug factors, disease factors and so on. 1. Lifestyle factors: when patients have unhealthy lifestyles, such as staying up late for a long time, drinking a lot of alcohol, and eating a diet high in cholesterol and fat for a long period of time, it will lead to liver damage, and the phenomenon of poor liver function will appear in the examination. 2. Drug factors: general drugs will be metabolized by the liver, when patients take too much drugs or long-term medication, it will lead to liver injury, resulting in liver function abnormalities, indicators of bad phenomenon. 3. Disease factors: when patients have liver diseases, liver cells will be degenerated and damaged or even necrotic, at this time, liver function test, liver function will be bad phenomenon. When patients have bad liver function, it is better to go to the hospital for examination in time, to clarify the cause of bad liver function, and to carry out treatment in time to ensure the health of the body.